Two C2610 connected via Serial V.35 cables.
R2 router S0/0 IP = 10.0.0.2
R3 router S0/0 IP = 10.0.0.3 (DCE)
On both routers, int s0/0 displays
s0/0 is up, line protocol is up.
However, I ping the IP addresses locally and ping is unsuccessful. What am I missing ? Config of r2 is shown below.
Current configuration : 651 bytes
service timestamps debug datetime msec
service timestamps log datetime msec
no service password-encryption
enable secret xxx
enable password xxx
no aaa new-model
ip address 10.0.0.2 255.0.0.0
no cdp enable
ip address 192.168.2.62 255.255.255.0
ip http server
line con 0
exec-timeout 0 0
When you can not ping the local interface it is frequently due to a mismatch in addressing between the two ends of the serial connection.
The reason that a mismatch of addressing can prevent ping to the local interface is because the ping to the local interface generates a ping packet which is actually transmitted over the serial, received by the remote router, and forwarded back over the serial. So if the remote router does not match up addressing with your router then ping will fail.
I notice that you message indicates that the serial addresses are 10.0.0.2 and 10.0.0.3. But the config that you posted shows that the 10.0.0.2 is on the Ethernet not on the serial. It looks like CDP is enabled on the serial interface. So a show cdp neighbor detail would be am easy way to verify whether addressing matches up correctly or not since the remote router IP address is shown in the show cdp neighbor detail output.
On r2 I did:
I did the same on r3.
Then I removed the 'router rip' from r3, and all of sudden ping was successful. It is working now.
In regards to "the ping to the local interface generates a ping packet which is actually transmitted over the serial, received by the remote router, and forwarded back over the serial." I've known this to be true for a while now, but why is this done? Is this done only on non-broadcast medium? It doesn't appear that this behavior exists on ethernet connections? Is there a document that describes Cisco's ping workflow as it relates to router architecture? Thanks.