Every time there is power outage in
the network, the router IDs change over to the Serial interface IP
address. This is causing a great deal of instability because every
time the router ID changes all the routers in OSPF Area 0 run
the SPF algorithm.
(NOTE: Do not erase routers from the
previous lab)
From the "Router C" console
- Issue the following commands:
- router-c(config)#interface
fastethernet 0/0
- router-c(config-if)#no
ip address 206.202.16.254 255.255.255.0
- router-c(config-if)#control
Z
- Are there any error messages? Why?

- Write the running-configuration to
memory and reboot "Router C"
- After the router boots enter enable
exec mode and issue the
command show running-config
- Is OSPF still configured properly?

- Issue the following
commands:
- router-c(config)#interface
loopback 0
- router-c(config-if)#ip
address 1.1.16.254 255.255.255.0
- router-c(config-if)#interface
fastethernet 0/0
- router-c(config-if)#ip
address 206.202.16.254 255.255.255.0
- router-c(config-if)#no
shutdown
- router-c(config-if)#router
ospf 1
- router-c(config-router)#network
206.202.16.0 0.0.0.255 area 0
- router-c(config-router)#control
Z
- Write the
running-configuration to memory and enter the command show
ip interface
What is the purpose of a loopback
address?

- Place a loopback
interface on "Router A" and then enter show
ip ospf neighbor
What is the router id of
"Router C"

- Add loopback addresses
to all the routers in OSPF area 0, write the running-
configurations of all the routers to memory, and then reboot all
the routers in Area 0
From the "Router A" console
- Enter enable
exec mode and issue the
command show ip ospf
neighbor
What are the router IDs of all the
routers in OSPF area 0?
