Why can't non-cisco server ping c3750 switch sometimes

[eric.huihk]

HI all,

I encounter a problem.

I have two devices interconnected. One is non-Cisco server and another is 3750 core switch.

If there are traffic between, the non-Cisco server can ping 3750. When there is no traffic, then server can't ping 3750.

But 3750 can always ping the server.

Is there any config i should set?

Thanks all,

Eric

[Richard Burts]

Eric

That is a somewhat strange symptom. I wonder if there is a mismatch in subnet mask between the server and the 3750? Can you post the exact IP address and mask from both the server and the 3750?

HTH

Rick

[eric.huihk]

The subnet mask is the same.

Server: 172.16.0.1 / 19

3750: 172.16.0.254 / 19

[dbobeldyk]

Maybe some sort of arp issue?

You can check the arp tables when there is traffic and when there is out. Just an idea on something to check...

[Richard Burts]

Eric

I agree with Denton that an ARP issue might produce symptoms like this. I would suggest that at sometime when there has not been traffic and so that the server is not able to ping the switch to run debug arp on the switch, attempt access from the server, and see if the arp request shows up on the switch and whether a response is sent.

HTH

Rick