Hello,

I have 2 cisco sw 3500xl series working properly forwarding traffic. All operations are Layer 2. I have setup keep alive 10 on all the ports. They are connected to another sw together with a Linux router on Cent OS 5.2.

I can't ping the switches from the Linux box. If I arping them, I get a response and after that they are accessible for telnet. Otherwise they are not.

After 5min the macs are flushed from the arp table of the Linux box, and then again they are not accessible only if I arping them, or set a static mac.

Do you have any ideas?

Thank you very much for listening to my problem.
Vlad

Turn on a sniffer to see the difference in the arp request from your ping and the arp request of arping. Also to know who is answering (maybe an proxyarp).
Or the interface is configured like this:
ifconfig -arp <blabla> which disables arp proto
?
try to reconfigure your interface
ifconfig +arp <blabla>

But the sniffer would be the best probably.