Information Technology Reference
In-Depth Information
C 192.168.1.0/24 is directly connected, FastEthernet0/0
C 192.168.2.0/24 is directly connected, Serial0/0/0
R1#
R2#
show ip route
Codes: C - connected, S - static, 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
i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS
level-2
ia - IS-IS inter area, * - candidate default, U - per-user static
route
o - ODR, P - periodic downloaded static route
Gateway of last resort is not set
C 192.168.2.0/24 is directly connected, Serial0/0/0
C 192.168.3.0/24 is directly connected, FastEthernet0/0
R2#
Verify interface configurations.
Step 2.
Another common problem is router interfaces that are not configured correctly or not acti-
vated. Use the
show ip interface brief
command to quickly verify the configuration of
each router's interfaces. Your output should look similar to the following:
R1#
show ip interface brief
Interface
IP-Address
OK? Method Status
Protocol
FastEthernet0/0 192.168.1.1
YES manual up
up
FastEthernet0/1 unassigned
YES unset administratively down down
Serial0/0/0
192.168.2.1
YES manual up
up
Serial0/0/1
unassigned
YES unset administratively down down
Vlan1
unassigned
YES manual administratively down
down
R2#
show ip interface brief
Interface
IP-Address
OK? Method Status
Protocol
FastEthernet0/0 192.168.3.1
YES manual up
up
FastEthernet0/1 unassigned
YES unset administratively down down
Serial0/0/0
192.168.2.2 YES manual up
up
Serial0/0/1
unassigned
YES unset down
down
Vlan1
unassigned
YES manual administratively down
down
If both interfaces are up and up, both routes will be in the routing table. Verify this again
by using the
show ip route
command.
Test connectivity.
Step 3.
Test connectivity by pinging from each host to the default gateway that has been config-
ured for that host.
From the host attached to R1, is it possible to ping the default gateway?
Yes
From the host attached to R2, is it possible to ping the default gateway?
Yes
If the answer is
no
for either of the preceding questions, troubleshoot the configurations to
find the error using the following systematic process:
