Cannot ping - serial interface

[cisconoobie]

I have a test lab setup and cant seem to be able to ping hosts that are connected over a serial connection, but I can ping from those hosts with no problem.

I have 2 Layer 3 switches and 2 2501 routers.

SWITCHA --(ethernet)--ROUTER1--(serial)--ROUTER2--(ethernet)--SWITCHB

From Router1, I can ping all interfaces connected on SWITCHA and ROUTER2 but NOT SWITCHB.

From ROUTER2, I can ping all interfaces connected on SWITCHB and ROUTER1 but NOT SWITCHA.

From SWITCHA & SWITCHB, I can ping any interface on any router or switch.

Is this becasue of a serial interface issue?

Router1 is connected to Router2 via a serial cable. Clock rate is set to 4000000 on Router2 serial interface so I can ping the interfaces with no problem.

Anyone know what this is?

[Edison Ortiz · Accepted solution]

When you ping from Router1, the source IP is the serial interface so Switch B needs to have this subnet on its routing table. It sounds like Switch B only has the Switch A subnet on its routing table and vice-versa.

Same idea is behind the problem facing Router2 towards Switch A.

[cisconoobie]

Yeah your right. I didnt see that lol.