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IP Addresses

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IP Addresses

  • An identifier for a computer or device on a TCP/IP network. Networks using the TCP/IP protocol route messages based on the IP address of the destination. The format of an IP address is a 32-bit numeric address written as four numbers separated by periods. Each number can be zero to 255. For example, 1.160.10.240 could be an IP address.

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IP Address Classes

  • Class A - 168.212.226.204
  • supports 16 million hosts on each of 127 networks
  • Class B - 168.212.226.204
  • supports 65,000 hosts on each of 16,000 networks
    • NDUS has two Class B addresses
      • 134.129.xxx.xxx Eastern ND
      • 134.234.xxx.xxx Western ND
  • Class C - 168.212.226.204
  • supports 254 hosts on each of 2 million networks

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IPv4 vs. IPv6

  • IPv4
    • 32 bits used for address
    • 4,294,967,296
    • Addresses not assigned by geographic region (see map)
  • IPv6
    • 128 bits used for address
    • 340,282,366,920,938,463,374,607,431,768,211,456
    • That about 3.7x10^21 addresses per square inch of the earth’s surface
    • Addresses will be assigned by geographic region

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IPv4 vs. IPv6

  • IPv4 addresses written as four octets (8 bits) separated by periods.
    • 134.129.67.235
  • IPv6 address written as eight 4-digit (16-bit) hexadecimal numbers separated by colons.
    • 1080:0:0:0:0:800:0:417A

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IPv4-to-IPv6

  • IPv4 Compatible Address
    • 0:0:0:0:0:0:w.x.y.z (or ::w.x.y.z)
    • Is used by dual-stack nodes that are communicating with IPv6 over an IPv4 infrastructure
    • The last four octets (w.x.y.z) represent the dotted decimal representation of an IPv4 address

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Loopback address

  • 127.0.0.0
    • Network number that cannot be assigned to any network
  • 127.0.0.1
    • The loopback address
    • Used for diagnostic testing of the local TCP/IP installation

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Automatic Private IP Addressing (APIPA)

  • 169.254.x.x
  • IP addresses are self-assigned when the computer asks for an IP address and no one responds.
  • i.e. the computer cannot reach a DHCP server over the network.

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Network & Broadcast addresses

  • You cannot assign a network number to a computer or any other host on the network.
  • You cannot assign the highest number on a network to a host. This address is interpreted as a broadcast message for the subnet.

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Reserved IP Network Numbers

Network number

Subnet mask

IP address range

10.0.0.0

255.0.0.0

10.0.0.1-10.255.255.255

172.16.0.0-172.31.0.0

255.255.0.0

172.16.0.1-172.31.255.255

192.168.0.0

255.255.255.0

192.168.0.1-192.168.255.255

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Designed for use on a private network behind a Network Address Translation (NAT) device, such as a firewall, proxy servers, or some routers.

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A NAT device can be used to disguise local or internal IP addresses from outside networks.

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For more reserved addresses see:

http://en.wikipedia.org/wiki/Reserved_IP_addresses

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Uniform Resource Locator

  • http://www.ndsu.nodak.edu/pubweb/~latimer/index.html#events

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  • http:// communication protocol
  • www.ndsu.nodak.edu web server hosting the page
  • /ndsu/latimer/ path to the page on the host server
  • index.html filename of the page
  • #events anchor in the page

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IP & Domain Name Examples

  • IP: 134.129.67.85
  • URL: gdc.busad.ndsu.nodak.edu

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  • IP: 134.129.67.235
  • URL: dyn235.minard-67.ndsu.nodak.edu

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ICANN

  • Internet Corporation for Assigned Names and Numbers
  • a private sector, nonprofit organization
  • responsibility for IP address space allocation, protocol parameter assignment, domain name system management and root server system management functions previously performed under U.S. Government contract
  • ICANN's diverse board consists of nineteen Directors, nine At-Large Directors, who serve one-year terms and will be succeeded by At-Large Directors elected by an at-large membership organization. None of the present interim directors may sit on the board once the permanent members are selected.

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IP Address Registries

  • Regional Internet Registries:
  • American Registry for Internet Numbers, ARIN
  • Réseaux IP Européens Network Coordination Centre, RIPE NCC
  • Asia Pacific Network Information Centre, APNIC
  • Latin American and Caribbean Internet Addresses Registry, LACNIC

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Internet Assigned Numbers Authority�http://www.iana.org/�

  • Generic Top-Level Domains
  • ccTLD Database (country codes)
  • IP Address Services

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New Top-Level Domain Names (TLDs)

  • ICANN is accepting applications for new TLDs.
    • Application window Jan. 12, 2012 to Apr. 12, 2012
    • Application fee: $185,000
    • Annual fee: $25,000
  • Intent is to move towards more descriptive names
  • Companies (organizations) can create
    • Brand domains e.g. .pepsi .coke
    • Generic domains e.g. .car .green
  • http://mashable.com/2011/06/20/icann-top-level-domains/

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