Static Routing - Routing Protocols and Concepts - page 113

On the R2 router, configure a static route to the 172.16.3.0 network using the Serial 0/0/0
interface of the R2 router as the exit interface.

R2(config)# ip route 172.16.3.0 255.255.255.0 Serial0/0/0
R2(config)#

View the routing table to verify the new static route entry. Step 4.

R2# show ip route

Codes: C - connected, S - static, I - IGRP, R - RIP, M - mobile, B - BGP
D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area
N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
E1 - OSPF external type 1, E2 - OSPF external type 2, E - EGP
i - IS-IS, L1 - IS-IS level-1, L2 - IS-IS level-2, * - candidate
default
U - per-user static route, o - ODR

Gateway of last resort is not set

172.16.0.0/24 is subnetted, 3 subnets
C 172.16.1.0 is directly connected, FastEthernet0/0
C 172.16.2.0 is directly connected, Serial0/0/0
S 172.16.3.0 is directly connected, Serial0/0/0
C 192.168.1.0/24 is directly connected, Serial0/0/1
S 192.168.2.0/24 [1/0] via 192.168.1.1

At this point, R2 has a complete routing table with valid routes to all five networks shown
in the topology diagram.

Does this mean that R2 can receive ping replies from all destinations shown in the topolo-
gy diagram? no

Why or why not?

Although R2 can route to all networks in the topology, this does not guarantee that other
routers can route back to R2.

Use ping to check connectivity between the host PC2 and PC1. Step 5.

This ping should fail because the R1 router does not have a return route to the 172.16.1.0
network in the routing table.

Task 10: Configure a Default Static Route

In the previous steps, you configured the router for specific destination routes. But could you do this
for every route on the Internet? No. The router and you would be overwhelmed. To minimize the size
of the routing tables, add a default static route. A router uses the default static route when there is not
a better, more specific route to a destination.

Instead of filling the routing table of R1 with static routes, you could assume that R1 is a stub router .
This means that R2 is the default gateway for R1. If R1 has packets to route that do not belong to any
of R1's directly connected networks, R1 should send the packet to R2. However, you must explicitly
configure R1 with a default route before it will send packets with unknown destinations to R2. Otherwise,
R1 discards packets with unknown destinations.