Floating Static Routes | Day 24 Lab – CCNA study notes Issue 19
Practice configuring floating static routes on Cisco routers using Packet Tracer (Free CCNA | Floating Static Routes | Day 24 Lab – Notes)
(Lab prepared by Jeremy McDowell)
Lab instructions:
In this lab we configure floating static routes, which are configured like regular static routes except we set a higher AD value so that a route is less preferred than a route learned by a dynamic routing protocol.
Static routes by default have an AD of 1. We can make the route a backup route by making the AD higher.
Enterprise A has two LANs: 10.0.1.0/24 connected to R1, and 10.0.2.0/24 connected to R2. R1 and R2 are directly connected by fiber-optic cabling.
R1 and R2 each have two Internet connections, one to ISP A with SPR1 and SPR2 (service provider routers 1 and 2), and one connection to ISP B with ISPBR1 and ISPBR2.
We are going to configure floating static routes on R1 and R2 to act as backup routes to allow R1 to reach R2 via ISP A even if a direct connection between R1 and R2 fails.
1. Check the routing tables of R1 and R2.
Which dynamic routing protocol is Enterprise A using?
Which route will be used if PC1 tries to access SRV1?
Which route will be used if PC1 tries to access remote server 1.1.1.1 over the Internet?
Test by pinging SRV1 and 1.1.1.1
Q. Which dynamic routing protocol is Enterprise A using?
A. OSPF
Q. Which route will be used if PC1 tries to access SRV1?
A. The most specific match is via 10.0.0.2, the OSPF route.
Q. Which route will be used if PC1 tries to access remote server 1.1.1.1 over the Internet?
A. The default route via 203.0.113.9 will be used.
Let’s look at R2’s routing table.
If PC1 tries to ping SRV1, when SRV1 sends the ICMP echo reply back to SRV1, R2 will forward it to R1.
Q. Test by pinging SRV1 and 1.1.1.1
A. First, let’s ping both SRV1 and 1.1.1.1 from PC1 to allow all of the devices in the path to complete the ARP process.
Then try the pings in simulation mode.
Note: 1.1.1.1 is a server somewhere on the Internet for our purposes here, but this is actually an internal virtual interface called loopback interface configured on ISPBR1.
Notice on ISPBR1 the loopback interface 1.1.1.1.
2. Configure floating static routes on R1 and R2 that allow PC1 to reach SRV1 if the link between R1 and R2 fails.
Do the routes enter the routing tables of R1 and R2?
We will configure one static route each on R1 and R2, using ISP A as an alternate path. Let’s start on R1.
OSPF has an AD of 110. So let’s go with 111.
R2 still needs its floating route for the return traffic from SRV1 to PC1 (if the link between R1 and R2 goes down).
3. Shut down the G0/2/0 interface of R1 or R2.
Do the floating static routes enter the routing tables of R1 and R2?
Ping from PC1 to SRV1 to confirm.
R2:
R1:
On pining again from PC1 to SRV1, the ping is successful.
>Using the traceroute tool:
To check the path traffic takes in a real network, use the traceroute tool.
In Cisco IOS the command is traceroute.
On a Windows PC the command is tracert, followed by the dst ip address, e.g.,
C:\>tracert 10.0.2.1
This command works like a ping except every L3 hop along the route to the dst sends a message back to the source. This command is helpful for troubleshooting and in making sure traffic is following the intended path.
Source:
Free CCNA | Floating Static Routes | Day 24 Lab | CCNA 200-301 Complete Course
https://www.youtube.com/watch?v=KuKC0G3LZc8&list=PLxbwE86jKRgMpuZuLBivzlM8s2Dk5lXBQ&index=46