Information Technology Reference
In-Depth Information
R1#
debug ip routing
IP routing debugging is on
Shut down the Serial 0/0/0 interface and observe the debug output.
Step 3.
R1(config-if)#
shutdown
%LINK-5-CHANGED: Interface Serial0/0/0, changed state to administratively
down
RT: interface Serial0/0/0 removed from routing table
%LINEPROTO-5-UPDOWN: Line protocol on Interface Serial0/0/0, changed state
to down
RT: del 172.16.2.0 via 0.0.0.0, connected metric [0/0]
RT: delete network route to 172.16.2.0
RT: NET-RED 172.16.2.0/24
RT: del 172.16.3.0 via 172.16.2.2, rip metric [120/1]
RT: delete network route to 172.16.3.0
RT: NET-RED 172.16.3.0/24
RT: del 192.168.1.0 via 172.16.2.2, rip metric [120/1]
RT: delete network route to 192.168.1.0
RT: NET-RED 192.168.1.0/24
View the routing table on the R1 router and observe the changes that occurred when the
Serial 0/0/0 interface was disabled.
Step 4.
R1#
show ip route
<Output omitted>
Gateway of last resort is not set
172.16.0.0/24 is subnetted, 1 subnets
C 172.16.1.0 is directly connected, FastEthernet0/0
R1#
Enable the Serial 0/0/0 interface and observe the debug output.
Step 5.
R1(config-if)#
no shutdown
RT: SETLASTRDB for 172.16.2.0/24
NEW rdb: is directly connected
RT: add 172.16.2.0/24 via 0.0.0.0, connected metric [0/0]
RT: NET-RED 172.16.2.0/24RT: SETLASTRDB for 172.16.0.0/16
NEW rdb: via 172.16.2.2
RT: add 172.16.3.0/24 via 172.16.2.2, rip metric [120/1]
RT: NET-RED 172.16.3.0/24RT: SETLASTRDB for 192.168.1.0/24
NEW rdb: via 172.16.2.2
RT: add 192.168.1.0/24 via 172.16.2.2, rip metric [120/1]
RT: NET-RED 192.168.1.0/24
Why is the route to 172.16.2.0/24 added first?
It is a directly connected network.
