Troubleshooting Multi-Player PC Game Connectivity Issues 

 Revision date: 21-Sep-2011


 © 2010, Rob 'Heycarnut' Cook, All Rights Reserved



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The purpose of this document is to provide assistance in troubleshooting connectivity issues when attempting to play on-line, multi-player PC games. It was written to consolidate findings from my work helping users with connection issues in BFBC2 and other games prior, but should be applicable to any game. This document is specifically targeted at PC games. Console and other peer-to-peer online games introduce additional requirements due to the use of peer-to-peer connectivity, however, much of the contents should still be applicable (see note:Consoles)


This is not intended to be a literary work of art, it is meant more as a 'brain dump' covering scenarios I've dealt with in many years of troubleshooting these kinds of problems. As such, I've necessarily dispensed with the normal niceties of a pretty format and flowing style, resulting in some rather fractured and condensed prose. Think of it more as a detailed checklist of ideas you can use. I hope the reader will forgive this needed compromise. In other words, don't turn this in as an English assignment, you'll get an F.



If you are unwilling or unable to do the footwork involved in proper troubleshooting, this document is probably not for you, and you might be better served by Internet forums or vendor support.


I make no apologies for the length of this document. There are a myriad of factors that can cause connectivity issues for online game play. Even generalizing troubleshooting suggestions for these to the point where any further minimization would render them useless, this corpus resulted. These factors can be very subtle, and factors that might seem totally unrelated can cause connectivity problems for games, either constant or sporadic. The reader may well miss some of these issues should they chose to skip parts of the document.


At the very least, if you are a PC gamer that is having connection problems that brought you here, search the document for references to 'port forwarding' to disclaim yourself of the most widely spread myth of modern PC gaming. A more detailed description about why the cries of 'You need to forward your ports!' should be met with disdain from the educated gamer can be found at Port Forwarding: Slaying the Mythical Dragon of Online PC Gaming.


Other quick reads that may serve as useful background information and clarification for some of the terminology in this document can be found at the author's blog, such as How could it possibly be my router causing connection problems?, for readers that are skeptical  that their router could in fact be their problem.


Disclaimer: Use the techniques outlined here with your head screwed on properly, I make no warranties, implied or otherwise, to their effectiveness, nor can I take any responsibility should you bork yourself, your hardware or your software.


These techniques have helped many, from PM & Email responses I've had, I hope they do the same for you. 


I welcome any comments and suggestions, I will update this document continually as I learn more from my own troubleshooting experiences, so do check back for updated tips.


Feel free to make suggestions or otherwise comment at or PCGAMETIPS@GMAIL.COM





Terminology Used in This Document:



The hardware (or software) providing an interface between your outside (WAN) and inside (LAN) networks. This may provide services such as NAT and firewall. This may be one device integrated with a modem. I will use a loose definition of router, in light if the intended audience using consumer level routers, and assume it refers to a device that has both router and firewall functionality. If you are utilizing a 'real' router and 'real' firewall systems in your environment, adjust your reading of my terminology as needed.



The hardware providing basic connectivity to the outside (WAN) network, typically provided by your ISP. This may provide services such as NAT and firewall. This may be one device integrated with a router. This may be a cable modem, fiber modem, DSL, aDSL, dial-up, or Satellite (see Satellite ISP).



Hardware or software that provides intrusion protection by controlling access from the outside (WAN) to the inside (LAN) networks. This may also control access from the inside (LAN) to the outside (WAN).



A component of an address used to communicate between network devices. Games typically communicate using several ports. You might think of this as the 'extension' used when 'calling' the address (IP number) of the server you are trying to reach.


Port Forwarding

The capability of a router to specifically manage, control, and direct network traffic from the outside (WAN) to the inside (LAN) networks, usually to a specific PC or PCs. Users that wish to run servers on their LAN that allow access from the WAN will usually need to avail themselves of this functionality when using a router. Some routers also offer functionality called 'port triggering'. This allows automatic port forwarding, triggered by specified outbound traffic.


Port Opening

Instructing the router and or firewall to specifically allow traffic over certain ports, usually but not always restricted to outbound traffic from inside (LAN) to outside (WAN) networks.



Network Address Translation. The capability of a router to multiplex multiple inside (LAN) connections over one outside (WAN) network connection. N.B., this is a perhaps a very oversimplified definition, but it suffices for this document. I do not differentiate between NAT, NATP/PAT, etc. for the purposes of this document, as consumer level routers seldom offer options beyond basic masquerading. NAT is a mechanism deceptively easy to describe, but wrought with complications in actual use. A comprehensive treatise on NAT and the ramifications of its use for applications is in itself a thirty to fifty page document (forthcoming). The reader may wish to review the surprisingly well written overview Network Address Translation on Wikipedia for an introductory treatment.



Your WAN provider (e.g., Comcast, AT&T, etc.)



Local Area Network. Your 'inside', private network.



Wide Area Network. The 'outside' network, effectively, your Internet. Where hosted game servers typically 'live'.



Network Interface Card. Your PC's physical network interface. Where you plug in the Ethernet cable if hard-wired.


Universal Plug and Play. A technology and protocol that allows UPnP aware hardware (routers) and software to interact and automatically configure themselves for connectivity. Found in most modern consumer routers. See UPnP for important caveats.


Bork: v. (bôrk): Irreversibly damage. 


Funambulist: n.  (fyooˈnambyəlist): Not used anywhere here, I just think it sounds cool.



I will use 'router' when discussing a stand-alone router, or the router functionality of an integrated modem/router device. Do note that many 'modems' provided by ISPs in fact are simple routers also, so do not assume because you have no stand-alone router that you could not be suffering from router related issues.


I will include 'firewall' functionality as part of the overall 'router' functionality. This is not usually strictly correct, but suffices for the needs of this document.


I will use 'modem' when discussing a stand-alone modem, or the modem functionality of an integrated  modem/router device.


I have perhaps oversimplified some use of terminology, in order to reach a wider audience. I apologise if this offends the sensibilities of experts.


I will use the bold italic font like that in this very sentence to denote important points, steps and cautions.





I will assume the reader understands the basic terminology listed above, and understands how to access the various hardware and software configuration we will discuss. Consult the documentation of your hardware (router, modem, etc.) and software if you are unclear how to access or configure them.  If the reader has built their own PC and network environment, they should not have any difficulties. If the reader searches their keyboard for an 'any' key when instructed to 'press any key', they may wish to enroll the assistance of someone comfortable with the contents of this document.


This document has a Flesch Reading Ease score of ~54, so it should be approachable for all of the intended audience.


It is  unfortunately well beyond the scope of this document to describe how to configure the reader's particular hardware or software. Should you not feel comfortable following the generalizations I am forced to use because of this, perhaps enlist the help of a tech-savvy friend to assist you.


The document will discuss only consumer level environments. If the reader is using a 'real' router and / or firewall, the configuration is likely more complex and beyond the scope of the document, and it should be assumed that readers with these kinds of environments understand the configuration issues involved with more advanced hardware and software.


Before embarking on the more invasive suggestions in this document, the reader should ensure the following are satisfied to minimize any potential for borking themselves. You may need these should you need to 'hard reset' your modem or router hardware.
















Depending on what issues may be causing the connectivity problems that have brought you to read this document, you may have been able to play other games without any problems, but find that a new game exhibits connection issues. Or perhaps you've always had issues with online game connectivity.


With any online game, there is of course the possibility that connection problems are caused by bugs in the client and/or server portions of the game. This is generally a pretty well exercised component of games, and it is unusual to see this as the source of the problems.


A good rule of thumb is unless a major segment of the player population is consistently experiencing the same connectivity issue, it is likely an issue with the user's hardware or software environment or caused by capacity limitations for the game and associated servers as opposed to a bug in the game. It is of course difficult to gauge what population of the player community is experiencing any issue, since usually only users experiencing issues post reports to forums, etc.


Nonetheless, it is highly unlikely that a bug or other issue in the game that causes any serious connectivity issues would not affect all players. This does not preclude the possibility that configuration and behavioral issues with the network infrastructure for the game may need tuning by the developers and / or game server providers for issues exposed during the initial 'honeymoon' of the game release, e.g., timing for heartbeats, timeout tolerances, server infrastructure and capacity limitations (game servers and/or centralised service servers), etc. These may require intrinsic configuration changes by the providers, and can also expose problems with the end-user's configuration or environment.


Players may not have experienced similar connectivity issues with games other than the game that led them to this document. Often, the assumption is made that since this is the case, it must be a bug or other intrinsic game problem. While this may point to a bug or other issues with the game, it can also be a patently incorrect assumption. The game having connectivity issues may require the use of ports that are currently improperly configured (while games that exhibit no issues have correct environmental configuration), or may have traffic patters that expose a weakness in the user-side configuration or behaviors.


Do not assume that because you've never had connectivity problems with other games that it must be an intrinsic problem or bug with the game. Unless a significant majority of users are experiencing the same issues under similar conditions, such assumptions are likely incorrect.Try to approach your troubleshooting with an open mind, and do not restrict yourself artificially with what may be misinformed assumptions (Note 1).


I will reiterate: The 'net code' of online games is of such fundamental 'low-level' importance to the infrastructure of online game play, it is by definition very heavily exercised during the development, Q/A, and any beta period for the game. Barring connectivity issues that are consistently experienced by most, if not all users, this dictates that it is much more likely that connectivity issues are a result of user configuration or environmental issues than caused by a fundamental flaw in the game. 


Do note that often during the initial period after the release of a game there may be insufficient server infrastructure for functionality of the game that is centralised and separate from the actual game servers. This includes authentication (login), validation of game ownership / DRM, game server browser query services, and player information services such as score, rank, achievements, etc. Insufficient infrastructure, or traffic congestion exacerbated by the typical deluge of online players to new popular games can manifest itself as connection problems for the player's initial login or server browsing activities. Depending on the game's use of these services, the player may also experience connection issues during the game, typically at the start and end of 'rounds.'


If you suspect the connectivity issues you are experiencing are a result of game server and/or centralized services overload or other capacity issues, these are likely out of your control, and should be reported appropriately to the game server and centralised services providers. This class of connection problem usually manifests itself as an inability of the player to 'logon' to the game, inability to browse game servers while in game, disconnections at the time of player stats updates or other interactions with centralized severs during the game.


I hope that by using the suggestions in this document, should the reader determine that in fact these kinds of infrastructure issues are the culprit of their connectivity problems, the game service provider will see that every reasonable effort has been made to diagnose any issues that could be on the player's side of the equation and take appropriate action.




The Problems:


Most connection problems with online games can be traced to one or more of the following:












We will review each of these below and provide troubleshooting ideas and suggestions for possible resolution.


I would strongly recommend that the reader absorb the whole document before attempting any of the suggestions. I will in fact assume this, and not reexplain items detailed in a section and then seen in subsequent sections. You may miss important steps or cautions should you choose to not heed this suggestion.


In addition, before assuming that connection issues are not caused by configuration or environmental factors under the reader's control, I would suggest the following:


If the reader has made any configuration changes manually to their modem, router, firewall, and associated software or to network hardware or software on their PC, I highly recommend that these are reset to factory / default configurations before proceeding.


All too often, advice, 'tweaks' and 'fixes' found in forums and elsewhere actually compounds the problems, and users may forget what they've changed, leading to undiagnosable problems.


Consult your user documentation for your appropriate hardware and software to accomplish this. This will help eliminate possible configuration changes the reader has made as being the cause of connectivity issues. I have seen too many cases where just doing this has resolved connection issues.


You can write down your current settings, and most hardware will have a mechanism to save existing settings to allow you to revert to them at a later time. Again, I highly recommend trying resetting configurations for your environment to default values before starting any troubleshooting, and I will assume this has been done, as it considerably simplifies the troubleshooting options!


Note that in some cases, if you make significant changes to router, modem, or PC network settings, you may need to 'reboot' the environment to properly communicate between devices.


If you seem to lose all communication when troubleshooting, simply power down all devices and PCs, then power up the modem (or integrated modem/router), wait a minute or so, power up the router, wait a minute or so, then power up or reboot the PC.



For the impatient:


If you are in a hurry to determine whether or not you can run the on-line multi-player portion of your game at all, and want a 'spot check' before embarking on a more detailed troubleshooting journey, you might try the following. 


  1. Disable all firewall, anti-malware, anti-peer applications that may limit network traffic on your PC.
  2. If using an integrated modem/router, configure the PC to be in the unit's DMZ zone and skip to step 8. Better yet, configure the modem for 'bridged mode' if it is not already operating in this fashion.
  3. If needed, configure the NIC on your PC so that it can properly communicate directly with your modem.
  4. Power down your PC, router and modem.
  5. Connect your PC directly to your modem.
  6. Power modem up, wait until WAN connection is established.
  7. Power the PC up.
  8. Attempt to play your game.


If this appears to solve your connectivity issues, the likely culprit is your router. If not, it may be the modem configuration, ISP limitations, campus or other network limitations, or a PC configuration issue. If the latter, follow the steps below to attempt resolution. Do note - depending on the configuration of your environment, this 'spot check' may expose you to a public IP address.


Even if this solves your issue, you should not run this way without an appropriate software firewall running on your PC or some other appropriate protection in place. Use the DMZ router zone only to test, when absolutely required, or as a last resort.


Check the router firmware revision you are currently using. There may be a newer version from the vendor that solves problems covered in this section, or perhaps third-party firmware such as dd-wrt, Tomato, etc.


Should you suspect that PC configuration is the culprit after this 'spot check', you may want to consider doing a re-install of your OS, or partitioning your hard disk and doing a clean, side-by-side install (Note 2) for test purposes of just your OS and the game, with no other unneeded software. This, while perhaps arduous, can eliminate OS and PC configuration as the source of your problems.


Failure to pass this 'spot check' dictates following the more detailed troubleshooting outlined here.




The Details:


These are in no particular order, feel free to use them in a sequence that you think applies to your case.


Before starting these steps, it is recommended you use the Internet Connectivity Evaluation Tool (ICET)  from Microsoft to do basic connection diagnostics.


This can at the time of writing  be found at


Follow the instructions provided, and in particular note the information under the 'Detailed Results', this may be useful in your troubleshooting attempts.


N.B. A failure on any of the tests is not definite indication of a problem that may manifest itself when attempting online game play, but may provide useful diagnostic information to use with the steps in this document.


By the same token, passing all the ICET tests does not automatically mean you will never experience game connectivity issues. It simply allows you to avail yourself of information that may aid in your troubleshooting, and to pinpoint gross configuration or behavioral issues in your HW /SW environment.


N.B., I've seen cases where improper handling of Explicit Congestion Notification causes issues with online games. This is normally disabled by default, but if you find that your router fails the congestion test and it is enabled, you can disable it in windows by issuing the command:

netsh interface tcp set global ecncapability=disabled




Improperly configured router

(e.g., ports manually blocked, improper or unneeded forwarding)


Consumer routers are in general designed to be fairly simple to set up and use, with minimal configuration required by the end-user. To do otherwise would result in routers that are confusing for the typical user, and cause support nightmares. Because of this, it is generally unusual for a consumer router to require any special configuration by the end-user to accomplish typical things like web browsing or playing online games.


In fact, with technologies such as UPnP, modern routers can combine excellent security with ease of use, by automatically configuring themselves on the fly, opening or forwarding ports only as needed by applications, and closing them when not needed. This increases the security for the user dramatically, while minimizing or eliminating any manual router configuration. In addition, most modern games can, at installation time and/or run time request windows firewall exceptions and port opening as required to run the game, so seldom if ever is any user configuration required to play an online multi-player game. Barring a misconfigured or misbehaving router, or a game that does not properly modify firewall exceptions and/or port requirements during installation and running, modern games generally need no manual configuration of any kind for routers or firewalls. This of course does not include more obscure host firewall software - these may not properly react to game installation or run-time requests, ad may need to have ports and other behavior manually modified by the user to run the game.


In general, consumer routers do not require the use of port forwarding to enable the use of the client for online games. This is usually only needed for users running a game server on their LAN that allows access from the WAN.


There are cases where an improperly behaving router may need to have ports forwarded to run a game client, as discussed in the router behavior section. 


If your router explicitly blocks outbound (LAN  WAN) traffic, you may need to open these ports in the router and / or firewall configuration. N.B., this kind of restriction is highly unusual in consumer routers as a default behavior, and you may not even see any configuration options for this in your environment. Some routers with UPnP capability may use this strategy, allowing UPnP to open the needed ports as required. You may need to enable UPnP on the router, and enable the appropriate configuration on your PC and OS if your router falls into this class and UPnP does not seem to be opening ports properly (see UPnP ). Most consumer routers do have mechanisms allowing the user to explicitly block ports and / or addresses for outbound (LAN  WAN) traffic, or provide other 'access restrictions' functionality.


Check to make sure you have not accidentally configured your router to block outbound traffic required for your game, and that any ports required by the game  are 'open', either because that is the default behavior of your router (nearly universal in consumer routers) and you have not manually blocked these ports, or by manually opening these ports if your router has this as an option and requires these to be manually specified (very unusual in consumer routers).


You can temporarily bypass all such restrictions (and any firewall functionality) in most routers by placing your PC temporarily in the 'DMZ' zone of your router. This may be useful to isolate router configuration or behavior issues. N.B., placing the PC into the DMZ zone of the router is often suggested as a 'catch-all' test, i.e., it is often suggested that if you still experience game connectivity issues when testing this way, it must be a game bug or other game issue. This is patently incorrect. Even when your PC is in the DMZ of your router, you may still suffer from problematic NAT settings or behavior, other router configuration or behavioral issues, or modem / upstream / ISP problems.


N.B. Steam users, according to steam/valve support "Steam does not support game-play on machines operating in a network DMZ. You must remove your machine from the DMZ in order to play through Steam." This is a most puzzling statement, I've never had any issue in this configuration, your mileage may vary.


If doing this solves your issues, check your router configuration and make any required changes for your game.


Note that this test may expose behavioral issues with your modem or router that you may not be able to resolve by changing configuration settings. See the router behavior and bug sections for details.


It is unwise to have your PC in the DMZ of your router as a matter of course. Do so only for testing purposes, or when otherwise absolutely required. Should you need a PC to be in the DMZ for extended periods, ensure that an appropriate firewall is running on that PC, or you are using some form of firewall protection as appropriate. Revert your PC out of the router DMZ when testing is completed.


Should you determine that in fact your router, either due to its default configuration, or configuration changes you've made, requires ports to be opened for the game, use the router configuration to properly specify the required outbound TCP & UDP ports. Be sure you understand that this is not forwarding ports (WAN  LAN traffic), but opening ports (LAN  WAN traffic) you want to configure.


Because of the fact that different games use different ports, it is not possible to list the required ports in this document. Refer to the game manual, game support staff or web sites / forums, or game enthusiast forums to determine the required outbound ports.


You can also use tools such as netstat to determine which ports a game is attempting to use for outbound traffic. N.B. in this latter case, some games will randomize ports between executions, complicating this method. It is best to get the port list from a definitive source such as the game developer or distributor.


To reiterate, in general you should not need to manually configure your router to play the client side of online games, other than perhaps opening, not forwarding ports. If you have manually forwarded ports or changed the outbound port or access restrictions of your router previously trying to solve connection problems, it is highly recommended you retry things with the router reset to factory defaults. 


In any case, consult the documentation for your router to determine if your router supports and requires ports to be manually opened or if you require port forwarding to run a server on your LAN, such as 'hosting' a game, or for PC and console games that use any kind of peer-to-peer connectivity component.


I will reiterate one more time:


In general, properly behaving and configured consumer routers do not require the use of port forwarding to enable the use of the client for online games. "You need to forward your ports..." is without a doubt the most widely promulgated piece of misinformed 'fix' advice for connection problems found on gaming enthusiast forums, and with modern games is patently incorrect for game clients and most routers.


Often such advice is accompanied with a reference to sites such as '', where the user can have a program automatically forward the ports on their router that allegedly require this. Think about this for a moment. Not only is this not needed by modern game clients, but what does the user  know of these programs? Have they been independently verified for correctness and security? Do the typical users even know how to determine if such programs manipulated only the allegedly required ports or open other vulnerable ports? Has the site been hacked, and in fact the program is opening ports with known vulnerabilities? For that matter, what about the ports bantered about on enthusiast forums and web sites? Does the user typically know if the suggested ports are even valid, much less required, or that they might include bogus ports with known vulnerabilities?


If the user doesn't understand how to verify this, use of these are unwise, in my opinion. And if a user does have this ability, they likely have the ability to configure their router manually, and probably understand that such forwarding is completely unnecessary.


Unless the game manual or developer specifically states that port forwarding (not opening) is required to utilize the game client, it is not needed. Unfortunately, many game manuals simply state 'ports required' with no clarification that outbound port opening is what is meant. Even more unfortunately, I've seen cases of well meaning game developers that clearly must not be involved in the network components of their game responding to forums  perpetuating the myth.


Note that some games allow the user to 'host' a game. In this case, the 'host' PC is directly or indirectly running the game's server, along with possibly the game itself. In these cases, the 'host' PC is acting as a server, and port forwarding may be required  for the server components of the game (if not automatically handled by the game via UPnP.) Some PC games will utilize other peer-to-peer communication techniques for multi-player game play instead of a centralized server. These kinds of games will also require manual port forwarding if this is not handled via UPnP automatically. Console games using peer-to-peer communications have similar requirements.


Port forwarding when it is not explicitly required can in fact exacerbate game client connectivity issues, and may complicate your troubleshooting. In addition, unnecessary port forwarding can expose you to unneeded security risks (you'd be surprised how easily one can suggest ports to forward for a game and have readers blindly follow that advice and in fact instead unlock a clear path into the users PC by exploiting known vulnerabilities.)


If you have manually configured your router for any port forwarding (or port triggering), and you do not have absolute certainty that these are required, and a clear understanding of their use, functionality, and ramifications they probably are not needed. Reset your router to its default configuration for these functions.


Most games will attempt to contact servers, either game servers or centralized services (patching/updating, DRM/Game ownership validation, game user login, game statistics such as MP rank, score, achievements, etc.) by a well-known name. This of course must be translated into the appropriate IP address via DNS (Domain Name Service), an integral part of your network services. If the DNS providers in your environment that are specified by your router or ISP you are utilizing are unreliable, the game may exhibit sporadic connectivity problems. If you suspect this may be the case, you may try a DNS test utility, such as DNS benchmark from GRC, available at the time of writing at . If you find that your default DNS provider is unreliable, replace it with one shown to have more favorable characteristics, and perhaps add one or more alternate DNS providers to the router list.


If your router has the ability to configure the NAT type, you may have a configuration that currently interferes with game traffic. This setting may have options such as 'cone', 'symmetric', 'Endpoint Independent', 'Address Restricted', 'Address/Port Restricted' or something similar in the configuration sections of the router that deals with NAT and/or firewall functionality. Certain NAT modes may interfere with game traffic, attempt to change these if your router allows this, and check if this resolves your connectivity issues. Some routers may have options such as 'NAT filtering' that may need to be configured or disabled to allow proper online game play. You may need to do an 'environment reboot' after making such changes for them to take effect. Other routers may have a 'game mode' (not to be confused with similar names used for wireless modes) that effectively turn the router into full-cone NAT, eliminating many issues with online games.


The ideal router for online gaming supports type 1, or full-cone NAT. Some routers will allow you to configure this, or have a 'game mode' that does this. If your router supports such configuration, use full-cone / Type 1 NAT if possible. This is a case where an exception can be made to the rule of never forward ports when not explicitly required. Forwarding ports on a router that exhibits undesirable NAT behavior can allow it to mimic a properly behaving router with full-cone / Type 1 NAT handling. Note that such a workaround may restrict the online game play to the PC on the LAN that the ports are forwarded to. This will also possibly mean users on the LAN side of the router will be unable to play the game online simultaneously. You may be able to work around this restriction by using the game's features to change ports for each player's PC to unique values.


Should you find that when attempting to connect more than one player on the LAN side of your router to the same game server on the WAN side of your router is resulting in the disconnection of an already connected player, this may indicate a NAT configuration or behavioral issue in your environment. Use the router configuration suggestions in this document to resolve these. If the router is properly configured, but you still experience this problem, it may indicate a behavioral problem with your router's NAT handling. Check if your game supports a launch option or configuration setting that allows you to manually set client ports, this may allow you to work around this particular type of problem. See the PC Configuration and Other Troubleshooting Options sections for further information and suggestions.


If your router has any Quality of Service (QoS) options, ensure that there are no artificial restrictions placed on traffic for the game, and that other traffic is not being given higher priority. If possible, make the game traffic the preferred priority. Some routers have questionable QoS functionality, try temporarily disabling any QoS features your router may have to determine if this might be a culprit.


If you have more than one router in you environment on the same network, this may cause issues with some connectivity scenarios. Some routers support Routing Information Protocol (RIP) that allows multiple routers to share information to optimize traffic flow. This may interfere with proper game traffic flow. If you fall into the rare category of user with multiple routers, disable RIP in all routers temporarily to determine if routing issues are causing your connectivity problem. You might also want to simply remove all other routing devices from your network temporarily to determine if they are interfering with traffic flow required by the game.


N.B.: Do not assume, should you find that other users using the same router are not experiencing connectivity issues, that your router is eliminated as the possible culprit for your particular issue(s). Consumer routers in particular are notorious for being wildly different 'under the covers', despite outward make/model designations being the same. For example, certain models of a major popular consumer router have a half-dozen differing chipsets, and at least two completely different OS kernels. Add to this changes between firmware revisions and the number of combinations of hardware, OS and firmware is quite large. This is in spite of the user interface likely looking and acting exactly the same: these routers will have the same manuals, configuration functionality, etc. exposed to the user, and are sold as the same model, but have fundamental underlying differences.


Unless you have the same make, model, hardware revision, and firmware version as another user that has no connection problems, your router should not be excluded as the possible source of your issues. If you do have exactly the same router as a user that is not having problems, configuration problems in your router or upstream problems (modem/ISP) may be the culprits.




Improperly behaving router (e.g. improper NAT handling)


Check the router firmware revision you are currently using. There may be a newer version from the vendor that solves problems covered in this section, or perhaps third-party firmware such as dd-wrt, Tomato, etc.


If you choose to update your router firmware, save your current configuration settings, these may be reset when flashing new firmware. If a new revision is available, update your router to see if this alleviates your issue(s).


The intrinsic mechanism used by routers to multiplex LAN  WAN traffic is not particularly well specified, and is rife with complications. In general, if your router and associated environment is cone or restricted cone type, as determined from ICET or other means, you should not have connectivity problems because of your NAT type. Other NAT types may cause issues with game connectivity.


Your router may properly handle NAT, but have a limited capacity for the number of entries used to keep track of connection states. This may in particular be exacerbated when trying to have multiple users on the LAN accessing game servers on the WAN simultaneously. Your router may provide information in its log that will show if this is happening, though very few consumer routers provide this level of detail.


Additionally, as outlined in the PC configuration section, other software can easily overwhelm the router NAT capacity, resulting in a loss of connection state. This is usually observed as a condition where users can connect to a game server, and the connection is lost at a later time, in spite of the game server functioning correctly.


Diagnostic options for this problem are rather limited for consumer routers.


Sophisticated users can use packet sniffing tools such as wireshark, or network sniffing hardware, to attempt to diagnose this issue. It is beyond the scope of this document to describe these procedures, and assumed that readers able to do this do not really need this document!


Some routers in my testing, appear to have truly bizarre behavior, where forwarding ports for the game 'fixes' NAT behavior. I have no explanation that is reasonable for this behavior, or for the 'fix' (Note 3). I would suggest if you try this and it 'fixes' the outbound port problems for your game client, it is time for a new router, or at least upgraded factory or third-party firmware.


Some routers in my testing, have unusually low 'timeout' values for NAT table entries, causing connection loss or an inability to connect at all when there is any delay in response from the game server during initial connection or game play. This can also be caused by a stall in client traffic through the router, resulting in NAT table entries aging out (unusual but possible.) Some routers tested had timeout values of under 20 seconds. This may be too low, particularly with heavily loaded servers or congested traffic, or when server 'heartbeats', if used, exceed this time span. Some routers have the ability to adjust these values. If yours does, you may try increasing these values for UDP and TCP, and see if it resolves your connection issues. If these values are not configurable for your router, check if newer factory firmware is available with this option, or try third-party firmware, or use a different router. If the game can be played using a VPN service, you can try this to determine if router timeouts might be causing issues - since the 'pipe' for the VPN connection is nearly always active, this will keep the router timer alive for itself, along with requiring minimal entries in the router NAT table, making it a valuable diagnostic tool for this kind of problem.


Typical users can attempt to narrow this down by either substituting a different router, preferably a completely different make and model, since problems like this can be familial. Success in this may indicate improper NAT behavior in the original router, though of course it can also indicate other behavioral or configuration issues with same.


The ideal router for online gaming supports type 1, or full-cone NAT. Some routers will allow you to configure this, or have a 'game mode' that does this. If your router supports such configuration, use full-cone / endpoint-independent / Type 1 NAT if possible. If proper NAT type configuration is not available in the router, and the user is unable or unwilling to replace it with a proper router, this is a case where an exception can be made to the rule of never forward ports when not explicitly required. Forwarding ports on a router that exhibits undesirable NAT behavior can allow it to mimic a properly behaving router with full-cone / Type 1 NAT handling. Note that such a workaround will restrict the online game play to the PC on the LAN that the ports are forwarded to. This will also likely mean users on the LAN side of the router will be unable to play the game online simultaneously. You may be able to work around this restriction by using the game's features to change ports for each player's PC to unique values.


Particularly bold users might consider flashing their router, if applicable, with third-party firmware, such as the superb DD-WRT, should they find that factory firmware even when updated, appears to exhibit problems. This can eliminate behavioral issues from factory firmware, though if the NAT table capacity is problematic because of a small RAM capacity in the hardware, this may not be the case. Use of such third-party firmware, and the methods to install it are clearly beyond the scope of this document, refer to the web sites and forums for them if you wish to attempt this. 


Backup your current firmware and configuration, or have the current firmware available before attempting this so that you can return the router to its current state should you need to. See the firmware site(s) and the documentation for your router for instructions.




Router capacity limits (e.g. NAT overflow)


Your router may properly handle NAT, but have a limited capacity for the number of entries used to keep track of connection states. This may in particular be exacerbated when trying to have multiple users on the LAN accessing game servers on the WAN simultaneously. Your router may provide information in its log that will show if this is happening, though very few consumer routers provide this level of detail.


As outlined in the router behavior section, there are a few things that users can attempt to diagnose this for consumer routers.


The use of software that creates, uses, and releases a large number of connections over short time spans (torrent, SIP, VOIP SW, VOIP phones (see VOIP Hardware ), etc.) may cause the NAT table in the router to fill rapidly, causing connections that the router considers 'older' to be flushed. This can result in an inability to connect in the first place, or a loss of connection sometime after successful initial connection.


Other devices using the local network can also cause similar flooding issues, such as media servers, SIP phones (Vonage, magicjack, skype devices, etc.). Temporarily disable or disconnect these from your environment to determine if these might be the source of your issues.


If this is a problem for your router, it may be exacerbated when multiple users on the LAN side simultaneously attempt to connect to game servers.


Unfortunately, very few consumer routers provide any capability to monitor or diagnose this. You may attempt to troubleshoot this by substituting a router known to work properly, or by packet-sniffing your traffic.


If this is diagnosed as your problem source, a new router, or perhaps new router firmware from the vendor, may resolve your issue. You may also find success using third-party router firmware applicable to your hardware.




Router bugs or other interaction (e.g. wireless, etc.)


Check the router firmware revision you are currently using. There may be a newer version from the vendor that solves problems covered in this section, or perhaps third-party firmware such as dd-wrt, Tomato, etc.


If you choose to update your router firmware, save your current configuration settings, these may be reset when flashing new firmware. If a new revision is available, update your router to see if this alleviates your issue(s).


If you are utilizing a wireless connection for your PC(s), try playing the game online directly connected to your router. Wireless communication can be unreliable and exhibit other stability issues that may affect the ability to play online without connection issues, and can also affect playability of the game itself due to possibly increased latency. In addition, interference from other devices such as portable phones, other wireless access points in your area, and other electrical interference can severely affect the reliability and/or speeds of wireless connections. Other devices accessing the access point may be using an inordinate amount of bandwidth, starving the game of traffic, causing it to exhibit connectivity problems.


If you are utilizing a secured wireless connection (and it should be secured as a matter of course), try temporarily disabling the security / encryption (WEP, WPA, WPA2, etc.) to determine if perhaps a problem with security / encryption handling between your router's wireless and your PCs may be causing an issue. It is preferred to have as high a level of security enabled on wireless systems as is practical, but there have been cases where this caused problems with online game play. Some routers have exhibited sporadic wireless problems when using more complex security settings, resulting in the loss of traffic for one or more users connected wirelessly. This has been seen on some routers to interfere with multiple players on the wireless LAN side being able to connect to a game server, i.e., a new connection causes a temporary connection drop of another already connected user.


If you are using a wireless router, particularly if PCs that are used for game play use wireless connections, and you are in a mixed environment (e.g., 802.11 a/b/g/n), your router may be suffering from interference from other wireless traffic. In addition, routers that support mixed environments will utilize 'Protected mode', since devices using differing 802.11 standards mean the default collision-avoidance scheme for managing traffic will not work. Using such a protected mode can impact traffic throughput by over 40%. However, in areas with a lot of other strong wireless traffic, using protected mode allows proper wireless operation. In general, if you are in an area with low wireless density, leave protected mode off for best wireless performance. In areas that may have high external wireless traffic (apartments, campus dorms, etc.), you may need to turn protected mode on to prevent interference that could impact game play. Your router may have settings called 'protected mode', or 'mixed mode', 'b/g mixed'. 'g only', or similar under its basic wireless settings. Experiment to determine if such settings might be affecting your game play. Of course, you must ensure that the client PCs support the particular wireless type you select.


Some routers exhibit connection stability issues on their wired ports when any wireless capabilities in the router are utilized. This is typically random in behavior, and the router may not indicate anything untoward has occurred. Some routers are known to randomly reboot when wireless is enabled, and unless the user observes the router indicators when this occurs, nothing else may indicate this has occurred. There may be entries in the router's log showing power events. Try utilizing your router with wireless capabilities disabled to determine if this is a cause of your connectivity issues.


If the connection issues are related to wireless functionality, updated firmware (factory or third-party) may resolve this issue. If this is due to hardware issues (bugs, overheating), a new router may be called for.


Some routers exhibit issues when IPv6 is enabled in the environment. You can experiment with disabling this in the router and in windows to see if your router shows unusual behavior under these conditions.


One router, in my testing, exhibited seriously broken UPnP functionality. In this case, disabling UPnP on the router resolved the behavioral issues. Disable UPnP on your router if you suspect this may be the cause of your connection issues. If your router's default behavior is to deny outbound traffic, you may also need to open the required outbound ports for your game when doing this. As already stated, denial of outbound traffic by default is unusual in consumer routers, but if you've previously configured any outbound port or access restrictions on your router, you may need to check to ensure you haven't accidentally blocked any required outbound ports for your game.


If your connection issues are resolved by disabling UPnP on the router, check if updated factory firmware is available that resolves this, or try third-party firmware, or replace the router with a properly behaving unit.


Do note that note that disabling UPnP functionality may adversely affect the operation of other hardware and / or software that utilizes this protocol.


Some routers I've tested have UPnP behavior that I find quite questionable. See Note 4.


As an example of how subtle problems on the user's end can give the appearance of an intrinsic game problem or bug, consider this: One user reported discovering that UPnP on their router could only be switched on/off by selecting the state and pressing the apply button, waiting for the screen of the router web console to refresh, and repeating this process four more times. This user tested this theory by rebooting the router and trying different ways to enable UPnP. Any reasonable person, seeing the connectivity problems this user had before discovering this, would quite naturally point their finger, incorrectly as it turned out, toward game bugs or other problems.




Upstream issues

(ISP or campus/corporate routing and / or firewalls impeding necessary traffic.)


N.B. Readers attempting to play the online component of a game that experience connectivity issues should pay particular attention to this section if they are connected to a network provided by a school or other campus, corporate networks, or any other network that is not directly connected on the WAN side via a consumer ISP.


Your ISP may be blocking or otherwise restricting traffic, either restricting ports and/or shaping or otherwise throttling traffic required for the game.


Query the support team for your ISP and check any forums for the vendor if applicable to see if this might be the case.


A quick test of this can be done by utilizing alternate primary connectivity options: If you have access to a wireless connection (preferably different ISP/router combination), or can utilize a cellular modem or tethered cellular phone for connections and see success, this may point to issues with the ISP / area networking configuration or settings, or possibly settings, configuration, or behavior of any local router if one is utilized. You may be able to narrow down possible culprits for connectivity issues to PC configuration or ISP / area network issues by using a VPN connection to the game servers and services over your existing equipment. Success with such configurations points to the ISP / area network (campus) as possible trouble spots, while failure may indicate PC configuration or any local router configuration or behavior as the prime candidates.


You may be fortunate and have an ISP / Campus IT / Corporate IT that will adjust such restrictions or traffic shaping to enable game play.


Readers on campus or corporate networks may need to query the appropriate IT organization to determine if this could be the cause of their game connectivity issues. Many campus networks severely restrict outbound and inbound traffic, or may use traffic shaping or throttling devices or software, either or both of which can impede your ability to play online games.


Many campus IT groups will open the ports needed by the game if provided with a list. Check in the game install guide and game associated forums and support sites to determine this list, or use a tool such as netstat from Microsoft to aid in determining what port(s) outbound the game client requires. 


You may also need to request a relaxation of any traffic shaping or throttling for traffic generated by the game. Ask the IT administration to verify that the port(s) required by the game are opened for outbound TCP and/or UDP traffic as required, that there is no throttling or other shaping for this outbound (or inbound response) traffic, and that there are no restrictions for inbound traffic for established connections from the campus LAN environment.


Players that are able to otherwise connect, and have acceptable ping / latency for their game, but are nonetheless experiencing 'lag' or 'rubber-banding' issues during game play may be suffering from traffic throttling or shaping policies on their campus / corporate network. Investigate this with the IT administration.


N.B. Despite all port requirements for the game being properly configured, it is possible that the NAT type or configuration for the campus LAN may prevent proper traffic flow for the game. If after the campus IT group configures the ports and ensures that no throttling or shaping is in effect you are still unable to play, but you can play at another location with the same hardware, this is likely the cause. Your options are very limited if this is the case, and barring the IT group being able to adjust these to accommodate you, game play may not be possible on your campus LAN.


Clever readers may realize that it is possible to construct an encrypted tunnel to an external proxy, and tunnel all game traffic through it. Such mechanisms can bypass restrictive LAN policy, and often any throttling policies, without requiring intervention by IT staff. Such a mechanism was constructed as part of the experimentation used for this document. While plausible for a single user on the LAN side, it becomes pretty gruesome to configure and use for multiple users. In addition such a mechanism would almost certainly violate the TOS for your campus LAN. Use of any such tools is left as an exercise for the reader, and assumes the reader obtains appropriate permissions as required...


Some upstream issues or restrictions can be bypassed (or narrowed down to a possible culprit) by playing the game through a VPN connection. Hotspotshield, Eztun, CyberGhost and Ivacy are examples of these services. Some specifically offer configurations appropriate for game traffic, some a free to use, most others offer some sort of no cost trial use period. Note that use of such a service may result in slightly higher latency/ping for your game play.




Improperly configured modem

(e.g., improper or limited configuration for integrated router/modems)


Some readers may be using a device with modem and router integrated into a single hardware unit. In this case, follow the router troubleshooting sections in this document for steps to diagnose possible configuration and behavioral issues.


Stand-alone modems may have built-in router and firewall capabilities. Using these at the same time as the connected stand-alone router may cause issues. NAT may be functioning in one of the devices in a way that interferes with game traffic. Double-NAT may exhibit issues with proper path MTU discovery, possibly causing connection issues. If you have reason to believe this may be a cause of your connection issues, adjust the configuration of the modem using the same steps outlined in the document for router and firewall configuration and behavior troubleshooting. Some modems may NAT only, others may have firewall capabilities, and some may act only as a bridge/gateway.


In most modems that have any kind of router capability, the modem can be configured in bridged mode, effectively bypassing these functions of the modem and utilizing the hardware purely for connectivity to the WAN. Using this mode with a properly configured router is preferred for environments with a stand-alone router and stand-alone modem, and can simplify configuration and troubleshooting. Consult your modem's user guide, and vendor support forums if you do not know how to configure your modem for bridging. N.B, not all modems support this, and some ISPs may disable this mode in their modem firmware.


If your ISP / Modem does NAT on its own (e.g., if you connect directly to the modem your PC gets a private IP address), this NAT combined with the NAT of your router can cause issues with connectivity. While properly configured NATing should be robust across multiple NAT environments, this is not always the case. You can attempt to adjust the NAT configuration or put the modem into 'bridge' mode, using your router for routing and firewall activity (preferred, in my opinion, as stand-alone routers typically have better functionality) and using the modem only as a bridge/gateway. In cases where it is not possible to 'bridge' your modem, you may be able to configure your router as 'bridged' to the modem. You router may have configuration options such as 'gateway/router mode' to change this behavior. In some cases, disabling DHCP on the router and setting the LAN address range and router WAN address to be in the LAN subnet of the modem can be used to effectively circumvent NAT on the router, utilizing it as a bridge only. You can also, if the ISP or other restrictions prevent you from bridging your modem, simply use a switch instead of a router to connect multiple PCs to your ISP's services, or cable the modem to a LAN port on the router (this will however disable any NAT/Firewall use on the router) to accomplish the same thing. You are of course in this case exposed to whatever router/firewall/NAT limitations your modem may exhibit. Because of the varying configurations of  hardware combinations, it is beyond the scope of the document to detail these configurations, consult with the user guides and support sites for your hardware, and with your ISP.



N.B. You may need to connect the modem directly to your PC to access any configuration capabilities. Follow the 'environment reboot' procedure noted earlier to ensure proper communication with the modem if this is the case.


Some modems provided by ISPs are configured by default  to very restrictive allowed outbound port utilization, and in some cases inbound ports are also restricted.


Check with your ISP to determine if they restrict outbound or inbound traffic by default in any way at the modem


If these restrictions are user configurable, you may need to adjust them in the same fashion outlined in the router and / or firewall configuration section of this document. Consult your modem's user guide, and vendor support forums for details and instructions on what is available for you to configure, and how to accomplish this.


Some modems provided by ISPs may have NAT configuration that interferes with game client connectivity.


In particular certain Alcatel/Thomson, Siemens and a few other units may require manual configuration of NAT Type (from symmetric NAT to cone NAT) and other NAT characteristics to allow proper game client connectivity. Consult the modem manual, and with your ISP support to determine if this may be the case and which configuration options you may need to change. These modem/router units may also require that outbound ports be opened explicitly to play online games. Check with your provider to determine if they in fact block the outbound ports needed for your game at the router, and for configuration changes you may need to make.


If the ISP is otherwise restricting traffic (port restrictions and/or traffic shaping or throttling) upstream from your modem, you may be able to request a loosening of these restrictions.


Remember that the 'capabilities' of your modem are likely controlled by your ISP, that is, more than just your link speed can be configured on the modem by the ISP. They can restrict what functions and configurations of the modem you are allowed to see and control. You may have to exert some friendly pressure on them should you believe there are configuration changes that could benefit you that have been made unavailable by their default modem policies.




PC configuration

(e.g., Software/Hardware on PC interfering with traffic, Network configuration incorrect.)


Anti-virus, anti-malware, anti-peer, torrent, VOIP, SIP, Skype, firewall (including windows built-in firewall), etc. can restrict traffic needed by the game client, or otherwise interfere with this traffic. Such software may also cause routers to rapidly lose NAT connection states, resulting in an inability to connect to game servers, or loss of connection some time after a successful connection to the server.


Disable all such programs temporarily to see if this is causing your connectivity problems. If successful, re-enable these piecemeal to try and narrow down which program(s) are causing your connection issues.


Note that there have been cases where disabling such programs is not sufficient to prevent them from causing issues. You may need to temporarily uninstall such programs to rule them out as interfering with your desired actions. E.G., it has been reported that the Comodo firewall, even when disabled, interferes with proper functioning of BFBC2. Certain anti-virus applications are known to exhibit similar issues. If in doubt, and to completely rule these out as culprits, uninstall them temporarily.


You may need to advise such programs / firewalls of exceptions for the game client program. In particular, if you have set such programs to a default behavior of deny access outbound (or inbound), and disabled notification from them, they may deny the game client access outbound, or server response packets inbound, without notifying you of the denial.


The windows built-in firewall generally handles these automatically, as do most program installers for applications that require outbound or inbound access, but it is always good to verify this with each and every program that monitors or controls network access in any way that is used in your environment.


While it is well beyond the scope of this document to detail NIC configuration, you may want to check these settings for problems.


Check the NIC driver version / revision you are currently using. There may be a newer version from the vendor that solves problems covered in this section. Get this from the motherboard or add-in card vendor's site. If using on-board NICs, it is usually preferable to get the drivers from the chip vendor's site when available, these are usually maintained more currently than those from the motherboard vendor sites. This has eliminated connectivity issues in many cases.


Some NIC have issues with power management, you might try disabling this temporarily in the NIC to see if this is a cause of your issues.


Some NIC may have faulty handling of such functions as offloading, check the various options in the advanced settings for your NIC and experiment with these. While there, ensure that no settings are set to values that might conflict with the rest of your environment (e.g., MTU).


Unless you have good reason to use a static address for your PCs, allow the PC to get address information from the router.


In general, the only time static IP addresses are needed is for applications (servers) on the LAN that require access from the WAN, and the router requires the destination LAN PC(s) to have a static address. In these cases, I prefer to use the 'address reservation' capability, if available on the router. It is in my opinion a more hygienic solution when some PCs on the LAN require static IP addresses.


Some NIC and routers exhibit issues when IPv6 is enabled in the environment. While preferable to leave this enabled, you can try disabling this on your router, if applicable, and within windows, to see if this is causing unusual behavior with your NIC or router.


If you have multiple NIC in your PC, or if you have software that creates any 'virtual' NIC adapters (e.g., Hamchi, VPN software, Virtualization such as Vmware), ensure that the 'real' physical NIC is first in your adapters & bindings list under the advanced network settings in windows. You will usually need to reboot your machine after you change the adapter in order for this to take effect.


If you have multiple NIC in your PC, try using an alternate physical NIC and / or NIC Port. If already utilizing an add-in NIC, try using the on-board motherboard NIC. If you only have on-board NIC, perhaps purchase or borrow an add-in NIC card and test with this in your PC. Success in any of these likely indicates an issue with configuration or behavior of the NIC you were using, or a problem / bug with the NIC hardware you were using. Do note the above caution about ensuring whichever NIC you are using is at the head of the adapter & bindings list in your advanced network properties.

Troubleshooting can be simplified in multi-NIC systems by disabling NICs other than the primary NIC used for gaming connections. This can be done in Windows and / or PC BIOS as required. This should include any additional “real” (physical) NIC and any “virtual” (VPN, Hamachi, virtual PC, VMWare, VirtualBox, etc.) ones.

Be aware that recent versions of windows altered the behavior of the windows firewall with respect to how rules are applied if NICs belong to different profiles. You may find that your primary/game NIC is having rules applied from other NIC profiles. If this is the case, adjust the NIC/network settings and/or firewall rules/functionality as needed. In particular, some virtual PC / Hypervisor / emulators have virtual NIC that register improperly in Windows, causing them to be classed with public profiles, resulting in a more restrictive profile being applied to the actual physical LAN NIC firewall rules.


Should you find that when attempting to connect more than one player on your LAN side of your router to the same game server is resulting in the disconnection of an already connected player, see if your game supports a launch option or configuration setting that allows you to manually set client ports.


Some game clients provide launch options to manipulate outbound port usage. This can help rectify issues where multiple players on the LAN side experience disconnection caused by poorly behaving/designed routers when more than one attempts to join the game server. Check the game manual and game related support and user forums for details. In the case of BFBC2, for example, adding the +clientport option to the game shortcut / steam game launch options seems to help some users with this particular issue.


If your game client provides no such option, or if it does but you still experience these kind of 'second player bumps first player' connection issues, it is most likely a router behavioral or configuration issue. Try changing the appropriate router settings, or substitute a different router to attempt resolution of this.


(BFBC2 Syntax:  "+clientport #", without the quotes, where # is a number unique for each client PC on the LAN side of the router, and is between 27005 and 27032. Some have claimed certain ports in this range are not allowed, or that the range is larger than this, I've not tested in any great detail. This syntax is for BFBC2, some other games use the same option, others have a different name or format, others do not have any such option. N.B., I have seen a DICE post claiming the option is in fact "-port #", less the quotes. Again, I have not tested this in any detail, consult an authoritative source such as the game manual or support forums for proper details.)


You may have a borked game installation. Completely uninstall your game, then go to any appropriate installation, configuration, and user data directories and delete any detritus that may remain. Reinstall the game and patches as required. If the game utilizes a anti-cheat system (e.g. PunkBuster), be sure this is properly updated. You can find the needed software, files, and instructions for this at the respective vendor's support sites. 


Disable or uninstall, temporarily, any and all anti-virus, anti-malware, etc. software during the installation process and initial and any subsequent patching process. Such software can corrupt downloaded content or patches, or in pathological cases interfere with local operations of the game installation processes and file operations resulting in corrupted game or game configuration. Reinstall or enable these when finished.


Certain games using PunkBuster have been known to experience disconnection issues when playing on PunkBuster enabled game servers. This can be caused by improper handling by your router of packets flagged as Out-Of-Band by PunkBuster. Use suggestions in this document to eliminate your router as causing this problem.


In some cases, PunkBuster may disconnect game clients that it sees as having the same IP and Port configuration, in particular when more than one player on the LAN side of the router attempts to connect to the same game server. This can be caused by router configuration and behavior discussed in this document. If you can connect and remain connected to game servers not using PunkBuster, this may be the cause of your connection issues, although in cases of pathological router behavior or configuration, the game server itself, or ancillary servers used by the game for centralised services may do the same.


You may need to manually update PunkBuster on your PCs. While PunkBuster is designed to automatically update, this has been known to be problematic. Use the PBSETUP application, available at the time of writing at to manually update your PC PunkBuster system.


You might also request the game server administrator check the PunkBuster server logs, these will indicate the reason(s) for disconnecting clients.


If port conflicts are causing PunkBuster to disconnect your game client, resolve this using suggestions in this document, or utilizing any launch options the game client may have to manually specify client game port options.


Most games will attempt to contact servers, either game servers or centralized services (patching/updating, DRM/Game ownership validation, game user login, game statistics such as MP rank, score, achievements, etc.) by a well-known name. This of course must be translated into the appropriate IP address via DNS (Domain Name Service), an integral part of your network services.


Your NIC may have these set manually, or receive them from your router or ISP directly. If the DNS providers in you are utilizing are unreliable, the game may exhibit sporadic connectivity problems. If you suspect this may be the case, you may try a DNS test utility, such as DNS benchmark from GRC, available at the time of writing at .


If you find that your default DNS provider is unreliable, replace it with one shown to have more favorable characteristics, and perhaps add one or more alternate DNS providers to the NIC list. If you are receiving DNS provider information from your router, make the changes required on the router instead.


Note that if you've suffered a DNS spoofing attack or similar, your DNS information may be incorrect and unresponsive. Also note that the mechanism windows utilizes to choose how to use the provided DNS providers is rather convoluted in environments with multiple NICs. In particular, ensure that the NIC used for the game is first in the adapters and bindings list in the advanced properties of network settings, and that other NICs in the system (physical or virtual) have proper DNS entries.


Check the hosts file (%windir%\system32\drivers\etc) to ensure that any servers the game may need to access are not having DNS overridden (there is seldom any reason for game related servers to have any entries in the hosts file. Such entries if not required can interfere with proper game connectivity.) Note that some system defense/protection utilities or applications (ad blockers, spyware utilities, integrated system protection applications) can add entries to the hosts file for sites deemed undesirable. Ensure that this is not occurring for sites/servers related to your game(s).


If you are utilizing a secured wireless connection (and it should be secured as a matter of course), try temporarily disabling the security / encryption (WEP, WPA, WPA2, etc.) to determine if perhaps a problem with security / encryption handling between your router's wireless and your PCs may be causing an issue. It is preferred to have as high a level of security enabled on wireless systems as is practical, but there have been cases where this caused problems with online game play.


Under some conditions, proxy settings (e.g., using a proxy for Internet Explorer or other browser) can affect some traffic needed for the game or game auto-update mechanisms. Check you browser and/or system settings to determine if you are currently using any proxy server. Should you find this to be the case, temporarily disable this and test game connectivity.


In rare cases, games may experience connectivity issues due to problems with packet fragmentation of traffic between the game client and servers. The user can try adjusting the Maximum Transmission Unit (MTU. see Path MTU Discovery) in their environment to determine if this is the culprit. In most environments, the MTU will be the default of 1500. Try lowering this value as applicable on the PC, router, and/or modem. This may be particularly applicable to users with PPoE connections. You may wish to consult with your ISP to determine if they require a particular MTU setting for your service. It is beyond the scope of this document to detail these settings, consult the documentation ad support resources for your hardware, and with your ISP to determine appropriate values.




PC hardware (e.g., NIC failure, cable failure.)


You may be experiencing a hardware failure with your PC NIC. If possible, obtain an add-in NIC card and test your connectivity with this. If already using an add-in NIC card, try the built-in motherboard NIC.


You may be experiencing an Ethernet cable failure. Try a different cable(s) between your PC(s), router, and modem where applicable.


You may be experiencing a hardware problem with your router. Substitute a known working router temporarily to determine if this is the case.


You may be experiencing a hardware problem with your modem. Substitute a known working modem temporarily to determine if this is the case.


You may be experiencing wireless interference. If playing over a wireless connection, try changing the wireless channel, or connecting the PC with a wired connection.


You may be experiencing router issues caused by wireless interference even if the PC is connected via cable to your router. Temporarily disable the wireless radio on your router to determine if this is a problem.




OS configuration issues.


There are many OS configuration options within windows that can cause connectivity issues with games. It is well beyond the current scope of this document to iterate these. A quick 'smoke test' can be done by either reinstalling windows, or partitioning your disk and doing a fresh side-by-side install (Note 2) of windows and the game. This will enable the reader to narrow the likely culprit(s) of connectivity issues to Windows and / or game installation / configuration problems.


Windows TCP stack issues,and windows socket stack or catalog issues though uncommon, can cause game connectivity issues. Should the reader suspect these may be involved in their issues (N.B. one would expect this would affect other connectivity) they can use the windows net shell to reset these to installation defaults:


Reset WINSOCK entries to installation defaults: netsh winsock reset [catalog]

Reset TCP/IP stack to installation defaults. netsh int ip reset <log_file_name>


In rare cases, particularly with aggressive filtering upstream by ISPs, the dynamic ports used may cause issues. These ephemeral ports can be checked in Windows Vista and later with netsh int ipv4 show dynamicportrange [tcp | udp]. These can be changed (assuming the game utilizes the OS port selection) with  netsh int ipv4 set dynamicportrange protocol=[tcp | udp] start=NNN num=XXX where NNN is the starting port and XXX is the number of ports to allocate. Note that starting with Windows Vista, the new default start port is 49152, and the default end port is 65535. This is a change from the configuration of earlier versions of Microsoft Windows that used a default port range of 1025 through 5000, so if your ISP is using filtering heuristics based on this, they may not have yet properly updated their filters, and changing these ranges may remedy problems this can cause.


Vista and Windows 7 introduce new mechanisms to enhance network responsiveness. Some of these may interfere with proper flow of game traffic. Specifically, these will give priority to multimedia traffic. Running media applications (music player, etc.) in the background while playing, or having a PC that acts as a media server to other PCs on the LAN may cause these features to be invoked, compromising game traffic flow. Try running only the game, or temporarily disabling any media serving on your PC, to determine if this might be a factor in your issues. There are low-level configuration changes available to alter these behaviors, however these are not recommended as they can negatively impact other aspects of performance in your environment. These will not be covered, use Google to find these if you chose to pursue this, and review


In particular, some routers and firewalls behave poorly in the face of Explicit Congestion Notification, introduced in Windows Vista / Sever 2008. This is generally disabled by default, but some 'tweaks' enable it. Use (in the command window) netsh int tcp show global to check the current setting and netsh int tcp set global ecncapability=disabled to explicitly disable this feature.


In some cases, the 'auto-tuning' features of the network facilities in Vista and Windows 7 can interfere with proper flow of game traffic. You can disable these with the command: netsh interface tcp set global autotuninglevel=disabled.


An oft repeated 'tweak' for games is to disable the Nagling for TCP via registry entries. This will not be covered here. Since the vast majority of game traffic is UDP, this has no effect other than placebo, and it is unlikely in my experience that any TCP traffic for the games I've tested benefit from this. 'Tweaking' this can also have deleterious effects on other aspects of network performance.


N.B.: I've seen no repeatable controlled test that shows any notable difference with the games I've tested using these 'tweaks', and believe that most users reporting a difference are suffering from placebo effects, or confounding variables. For example, one group of gamers I work with thought there was a remarkable improvement after disabling auto-tuning. Much to their dismay, it was shown Windows had re-enabled it, and they had been playing with the same settings as before their 'tweak'. Should you still insist on using this, remember to disable heuristics with netsh int tcp set heuristics disabled.


There are a couple of corner-case exceptions where this setting appears to be useful: Some older NATing routers with stateful inspection may have problems with the 'normal' setting causing slower speeds and packet loss. Really old routers may have issues and not properly support TCP windows scaling. In particular, some router models using SPI (Stateful Packet Inspection) firewalls can exhibit apparently sporadic connection behavior for non-http connections in the face of tcp window scaling (Vista/W7). Disabling this in windows, or disabling the SPI functionality of the router may resolve such incompatibilities.



Before using these potentially destructive commands the reader should fully understand the ramifications of them, and make note of any components that may be removed or modified by these commands so that these may be returned to the desired configuration. In particular, resetting the winsock catalog may disable proper functionality if other programs, browser add-ons / toolbars, firewalls, and antivirus applications. MSINFO32 can be used (under components, network, protocol) along with the 'show global' of netsh to observe the components present to aid in determining if there is a problem, and to make note of applications that may need to be reinstalled to restore functionality after resetting the catalog.


Some 'protection' programs will modify the hosts file, overriding DNS, to prevent pop-ups, ads, or access to sites deemed 'malicious'. Check your hosts file (%windir%\system32\drivers\etc) for any entries that might be redirecting access to services needed by your game.


ISP upstream issues.


If all else fails, you may be suffering from issues that are out of your sphere of control.


You infrastructure may be causing noise / dropouts on your connection (e.g., DSL on sub-par wiring, cable on sub-par cable, insufficient signal strength, insufficient S/N ratio etc.)


Consumer options are limited for diagnoses of these issues. Contact your ISP and request a line quality test, or a long term line monitor.

Some older NID/SNI at homes have diagnostic chips that are generally not used anymore. These have been found to sometimes interfere with connectivity, in particular for DSL users. If you avail yourself of a home visit by a tech from your ISP, ask them to ensure such unneeded devices are not present, and if they are to remove them. I have seen these affect throughput and cause intermittent, random loss of WAN connectivity without any modem error log entries produced. This can be a quite puzzling symptom.

You might ask your ISP to provide a "home run" or dedicated run for your service. This will isolate it from any shared signal, and can improve throughput and reliability.


Request the ISP check the quality of your signal(s) and infrastructure with a site visit. Run an online quality check (google for isp line quality check or packet loss test) to see if perhaps there are gross problems with your connection reliability upstream from your hardware.


Tools such as Ping and Tracert can be used for very rudimentary testing of your connection to servers. Do note, tracert is often recommend in forums as an incredibly useful tool to find problems upstream. Unfortunately this is not really correct. Tracert provides rather limited diagnostic value for anything other than gross network path issues (one-way with very limited return path information in some cases), and proper interpretation requires fairly deep knowledge and ideally access to both ends of the connection. I would go so far as to say the vast majority of tracert interpreted in forums as indicating issues are in fact showing correct behavior. If the analyst can't tell from a tracert column such as what kind of router and the speed and port used for the hop, they probably aren't in a position to interpret the results in any great detail. It should also be remembered, Microsoft's implementation uses ICMP instead of the UDP protocol, resulting in low priority and blocking of the packets, clouding any results.


For DSL users, you may wish to check your DSL Modem/Router for its FastPath/Interleaved status. Interleaving is an error correction mechanism common in DSL environments that can significantly reduce sync and data errors in areas with line noise issues. Your provider may call this 'putting the user on a noise profile.' While interleaving can significantly aid in alleviating such problems, it comes at the cost of greatly increased latency. In some cases, this increased latency can cause connections to game servers to be dropped. Unfortunately, in the interest of reducing support calls, many ISPs default to interleaved mode. The alternative is called FastPath. You may be able to switch this in your particular hardware, or it may require contact with you ISP to enable this. Note in any case, should you pursue this, you may still need to contact the ISP to ensure that FastPath is also enabled for your port at the DSLAM.


Make sure your ISP in not limiting, traffic shaping, or otherwise throttling traffic required by the game. Persistence may be required here, many ISP first level support staff will often deny, or otherwise be unaware of such policies. Some ISP offer an extra charge 'gamer mode' or the like that use policies appropriate for games. Rather than succumb to such robbery, if another ISP is an option for you, you might pursue this. I've found that 5-10% of connection problems for some games can be traced back to ISP issues or policies.


See note 5 for more details of some peculiar upstream ISP issues.



Other Troubleshooting Options.


In some cases, arduous as it may be for users (excepting those that game on a laptop), it may be worthwhile to move your gaming platform to a completely different location (e.g., a friends house), ideally one that utilizes a different ISP and / or connection type and differing router / modem hardware, and that is running the same game without problems. You may find your game runs without problems with this change. If this occurs, it clearly points to issues that likely have nothing to do with the game itself, and are router, modem, or upstream. If the remote location has another PC that you can install the game on temporarily, try this. If it runs correctly, while your own PC exhibits issues, it clearly points to configuration or behavior issues with your OS, hardware, or game installation.


Consider also taking the router and / or modem to a different location, ideally to perhaps the location of a friend that runs the game without experiencing connection issues. If substituting your hardware causes connectivity issues on their PC, it is most probable that router and /or modem configuration or behavior is the culprit. N.B. depending on the type of modem and ISP restrictions, you may not be able to substitute your modem for one at a remote site. You certainly won't harm anything trying this, but the connectivity of the modem may be restricted to certain segments (cable) or otherwise restricted. In general DSL modems are reasonably portable in this sense. This may require that you have the phone service provider for the remote site enable DSL at that location. This can be done for nominal cost for a short term test.


Consider borrowing a modem and / or router from a friend that plays the game without issue. Substitute these into your environment (with the came caveats as above) and test if connectivity issues are resolved. If using a cable / fiber modem, you can also try a friend's DSL modem to eliminate cable or fiber infrastructure issues as a culprit, as these tend to be quite unrestricted in where they can be used. This may require that you have your phone service provider enable DSL at your location. This can be done at minimal cost for a short term test.


N.B. if you attempt to substitute routers or modems as part of your troubleshooting, you may need to follow the 'environment reboot' described earlier, and may need to change your PC network configuration, or the router configuration, to ensure proper communication between the devices and your PC.


You might have a friendly neighbor that has a wireless access point enabled. If your PC has wireless capability, or by purchasing or borrowing a wireless NIC, you may benefit from trying to run the game over their network infrastructure. As stated elsewhere, if you desire to try this test, make sure the wireless NIC is at the head of your adapters & bindings list in your advanced network settings. Of course, ask permission of the owner of the access point if it is unsecured, it may be a violation of local laws to 'poach' network access. If you have access to strong but secured wireless access points, you can perhaps ask the owner for temporary access. A bottle of good wine can go along way!


Should you find resolution of your connectivity issues by such measures, you may need to further investigate configuration or behavioral issues for your equipment, and you certainly have ammunition to use with your ISP to enroll their help for more a more sophisticated examination of your issues from their end.


A troubleshooting option for readers with stand-alone routers (i.e. router and modem are separate devices) and multiple PCs available, with at least one of them having two NICs, is to use one of the PCs as the router, utilizing Microsoft's own Internet Connection Sharing (ICS). This may enable you to exclude your router device as the source of your problems.


Players on a lan attempting to connect to the same game server that are experiencing the 'second player joins, first player gets kicked or loses connection' class of problems are in an ideal position to utilize this method if another router is unavailable for testing. ICS should be setup as a minimal router, with all firewalling, etc. disabled for the testing. Appropriate measures should be used to protect the system (re-enable firewalls, etc.) should the reader find success with this method and choose to utilize it  long-term. It is beyond the scope of this document to detail the use and configuration of ICS, search the Microsoft web site or consult your windows documentation for information.


You can eliminate the router/modem/ISP loop by utilizing a cellular phone with tethering capability, or a cellular modem. With 3G/4G capability, these have more than sufficient bandwidth and latency for a single client player. Proper functioning of the game utilizing such connectivity methods would indicate detailed troubleshooting of the router/modem/ISP loop.


DSL/aDSL users may want to temporarily remove phones connected to the line used by their DSL modem. Some phones have an excessively high Ringer Equivalency Number, and can interfere with DSL modems even when properly filtered.







(1) An informal sampling of users playing or attempting to play what appeared to be a particularly troublesome title, where the author either had direct interaction with their hardware environments or detailed remote interaction, exhibited the following characteristics.





Based on these results, it appears unlikely that the connectivity issues reported by many users in this case are intrinsic to the game code itself. A reasonably large sample of users with varied hardware configurations, but having well behaved and properly configured environments experienced no significant connectivity issues over a several week period of game play. The users that had reported issues, after reconfiguration of their environment, reported a similar lack of any significant connectivity problems.




(2) A 'side-by-side' installation is a technique whereby the user uses an available free partition on their hard disk, or shrinks an existing partition with the current windows installation to make room on the disk for a free partition. This allows a 'clean' install of windows to coexist with the current installation. This can then be used to install the game, allowing the user to test in a completely hygienic environment, free from possible configuration issues or software interference. This allows for rapid troubleshooting while keeping the original windows installation untouched. If the test is successful, the user can then piecemeal determine what in the original OS and / or game installation is faulty. In any case, when done, the side-by side installation can be removed and the free space returned. If the user does not have an existing free partition to use they can use free tools such as the bootable GPARTED CD to accomplish partition shrinking. Alternatively, the user can install the side-by-side on a secondary disk with appropriate free partition space.




(3) In tracing some traffic while continuing a mass test of some consumer routers (around two dozen at this point), I've found that ~25% of them exhibit some kind of behavior (at default settings) that renders their NAT usability in PC gaming questionable. The majority of these can be configured for the desired behavior, but I did see one router that exhibited puzzling and possibly faulty NAT behavior.


Observing traffic, I had the thought that perhaps the reason some users seem to resolve connection problems using port forwarding where in fact no port forwarding should be required may be this:


The router has insufficient NAT table size to handle the activity, or has timeouts so low that it ages out entries too quickly, either generally or in the face of delayed server responses due to load or traffic congestion. In this scenario, it appears that having the ports for inbound traffic forwarded to the destination PC allows packets that would normally be NATed to that PC but are rejected due to NAT table entry aging to still get routed correctly to the destination.


Depending on the characteristics of the router, and timing of the traffic, there may in fact be ping-ponging by the router between delivering the inbound packets via the 'correct' (NAT) method, and delivering them via the 'incorrect' (port forwarding) mechanisms. I will attempt to construct an appropriate acid test for this theory, since there is no way in any of the consumer routers I am testing to observe the details of internal behaviors, and this must be deduced from external data and behavior. I may also jigger up a test software router with characteristics to mimic this model to probe if this behavior is plausible. Far-fetched and a wacky hypothesis, indeed, it should make for some interesting diagnostics.


Another possibility for this behavior could be a router that defaults to deny all for outbound for all traffic, or for traffic on the registered and/or dynamic ports but automatically opens outbound traffic for any ports forwarded to the LAN, regardless of established connection state or lack thereof. I have never seen a router with such behavior, but it seems plausible for a consumer router where the firewall logic was designed with (faulty, IMO) assumptions about what the user wishes to accomplish when forwarding a port. Should any reader have knowledge of such behavior, please email me with details.





(4) Certain popular and widely used Broadcom based routers (e.g., WRT54 series by Linksys) maintain UPnP port mappings in NVRAM as a 'convenience' for the user. These same devices are limited to 32 entries for this table. Unfortunately, should a request be made via UPnP to add an additional mapping when the table is full, the device will return success, but will not actually add the mapping. This can cause the game to 'think' the mapping is there, when it is in fact not. There is no user interface to clear such mappings in most factory firmware. Only a factory-reset via menu or the reset button will clear this table. Some versions may clear the table if UPnP is toggled between on/off/on.


Devices using the 'router' UPnP stack increase this limit by a factor of five, but still suffer from not properly returning an error for an already full table. The stack table can be reset by cycling UPnP through on/off/on.




(5) In investigating a particular class of connection problem I was diagnosing, I found peculiar traffic originating from a centralized server associated with the game, as an unsolicited  inbound request. I found this most puzzling, and made contact with an engineer at the game publisher's NOC. This particular provider utilizes software that attempts to do route optimization, and uses outbound (from their server to the game client IP) packets to do so. In this particular connectivity problem case, the ISP of the user had equipment and policies that heuristically identified these packets, due to their port range and direction characteristics, as spam/malicious, resulting in an automatic black-listing of the server IP for their subscribers. A call to the ISP provided remedy by them white-listing the server IP range. A lesson: If you suspect an ISP upstream issue, get yourself to a higher level tech. as quickly as possible, since front line tech. support would likely be completely unaware of such automated mechanisms.




(Consoles & PC Peer-to-Peer) Modern consoles and some PC peer-to-peer games utilize features that require the client to in some cases act as a receiver / server of certain traffic. You can effectively replace the use of server in the document for console / PC P2P games online. For these, and only these cases, there may be a requirement to forward ports to the console/PC Client. With modern routers, this will almost always be properly handled automatically via UPnP, giving the best combination of ease of use and security. However, should manual intervention be required, refer to authoritative sources for the ports required by the game, and which must be forwarded vs only opened. Note that some sources for this information may inaccurately term forwarding of ports as opening of ports. Try to determine the correct needs, but if all else fails you may need to forward all ports listed for the game. If this can be done with port triggering, you can still have a relatively secure environment, as the ports will only be forwarded while playing and for a short timeout period afterward. Otherwise, should you find forwarding all ports listed for the game allows proper functioning, it behooves you to selectively remove forwarding on a port-by-port basis, so that only the actual ports that require forwarding have it set. This will give you the least compromise in security for your environment. Enabling Internet NAT redirection/local loop-back/reflection (also called many other names, refer to your router documentation) may be useful if using multiple clients on the LAN side of your router. Do note, some games will publish the address of peer-to-peer servers using the external IP address of the router, and may not provide for discovery and/or connection to such servers using internal (private) IP addresses. Utilizing the aforementioned redirection capabilities of the router should allow “LAN party” play with only local, private IP clients.


XBOX users can avail themselves of the built-in NAT testing feature under the dashboard. The NAT results will show as follows:


Strict: Your NAT is symmetric.

Moderate: Your NAT is Cone, with port filtering or with UPnP turned off.

Open: Your NATis Cone, with no port filtering or with UPnP turned on.


Configure your network as needed to get an 'open' result for optimal game play.


n.b.: I have noted a behavior in a few routers tested when using UPnP, and in some third-party firmware also, where attempts to connect multiple clients (PCs or XBOXs) results in one device getting an 'open' rating, others getting more restrictive ratings. In some cases, symptoms also included disconnection of one or more clients after some time elapses during game play. I have traced this to a bug or non-standard behavior in the use of the UPnP InternalClient value. In these cases, setting the router to use DHCP reservations for the client(s) resolves these problems (assuming, of course, that the router can provide 'open' NAT in the first place.) Attempting to use static IP addresses for the affected client(s) did not result in resolution, you must use DHCP reservations. I have no reasonable explanation for this behavior, and lacking access to firmware source, one is not likely forthcoming.




(Satellite ISP Users) Users attempting to utilize satellite Internet will likely have difficulties attempting to play FPS games online. Games with a slower pace not requiring 'twitch' reaction times (e.g. World of Warcraft) may play acceptably.


The problem with satellite ISPs is not speed: they have plenty for games, which seldom even need 100Kbps, it is the latency. The satellites used for typical consumer ISPs are geostationary, otherwise you'd have to have your dish following them around. To be geostationary, they are at a certain distance from the earth. Roughly, the latency each way because of the distances involved ranges from 250ms to 900ms, depending on the position of the satellite used and how the traffic is handled between the link station and backbones. This means a round trip latency of at least 500ms (half a second) up to 1800ms (nearly two seconds). You'll have trouble playing any fast-paced game with those kind of delays.




(Path MTU Discovery) Over certain IP routes, attempts to send packets with large payloads may fail, while smaller payloads function correctly. This behavior is usually unidirectional, that is, only happens for inbound or outbound packets. This is usually a symptom of problems with the Path MTU discovery failing. This applies to TCP packets, UDP is not affected (Strictly speaking, this is not correct: It is possible to do PMTUD on UDP packets, but it is seldom enabled or utilized due to the difficulties in retransmission design for applications). This problem often manifests itself in environments using PPPoE (DSL) connectivity. Users may see no issues when utilizing PPPoE client-side software to connect, but have issues when using PPPoE via their router. This is due to the PC seeing the MTU of the router (usually 1500), and not being able to detect that the router is using PPPoE for the actual connection, thereby assuming 1500 is the MTU. The responding server will also see this 'overloaded' MTU for responses. You can probe MTU characteristics for the path to the desired server utilizing ping  -f  -l  L X.X.X.X, where L is the packet size, and X.X.X.X is the IP address of the server. Start L at some value (1472, 1464 is good for PPPoE connections), and observe the results. If you receive "Packet needs to be fragmented but DF set" instead of a ping reply, drop L by 10 and retry. Once you get a ping reply, retry the ping, incrementing L by one, until the "Packet needs to be fragmented but DF set" response returns. The MTU of the path will be L-1+28, where L is the value for the ping where the "Packet needs to be fragmented but DF set" message was returned. You can then make the necessary adjustments to your environment to utilize a correct value.




(VOIP hardware) Users of VOIP hardware such as Skype, Vonage, Magic Jack, and other ATA VOIP adapters may be experiencing interference from these devices. This may be from the amount of traffic generated and the rate at which connections are made/broken, or other issues with how the hardware handles network traffic. In particular, users of ATA adapters that instruct the user to place the device between any modem and router (Wan/Modem  ATA/VOIP Device  Router PC) may wish to experiment with an alternate configuration of  (Wan/Modem  Router ATA/VOIP Device & PCs on router ports) this should function normally in most cases, and may alleviate any untoward network behavior caused by the ATA VOIP device marshaling network traffic. Some ATA devices are in and of themselves routers. These may need configuration in addition to the user's 'real' router, and may suffer from the same behavioral issues as malfunctioning or questionably designed 'real' routers'. Using such ATA devices serially may introduce problems with proper NAT handling (E.G. Path MTU Discovery can break under double-NAT environments). If problems persist, it is suggested that all devices utilizing the network other than the basic modem, router, and PC be temporarily removed from the network. If this resolves your problems, you are likely suffering from the router being overloaded by traffic from the other devices, or problems with the other devices themselves.




(UPnP) Note that prior to Windows Vista, UPnP is not usually enabled in Windows by default. To properly utilize UPnP in your environment, you will need a router that supports UPnP (and has this enabled), and the OS must be configured to use UPnP. For Windows XP, if UPnP is not already enabled, follow these steps to enable it:


(Thomson / SpeedTouch / Alcatel, et al. users) I have noted some commonalities with users having these products having disconnection / router reset issues. In particular, gamers utilizing the Steam platform from Valve often experience disconnection and server browser issues with some models of these “brands”. I have seen success with the following:



(7) Need to know something about me? Where I hang out lately when not gaming.



(8) A cool animated image I made using Mathematica. This shows the result of calculations using the orbital elements of the earth to determine their effect over a one year period on the Equation of Time and the resulting Analemma of the Sun. Here just for the fun of it!


Equation of Time and Analemma animated graph.