Hi, I've had some strange problem at a customer site ... setup generally looks like this: two 3560 (call the A and B), connected to each other via 2 port etherchannel, each of the two connected via one fiber link to a Linksys SRW 2024 (called L). STP blocks one of the fiber links (let's say between B and L), everything looks good on layer 2/3 ... Multiple VLANs are in use, which are trunked between the Ciscos and the Linksys, though only 4 VLANs are actually in use on the Linksys (the others aren't configured).
Now for the problem, I can't seem to get any ARP requests through from the Cisco switches to the Linksys, at least not from anything further than A: I can ping anything connected to L from A, though neither B nor other hosts hooked up to A can reach anything connected to L. I did a "debug arp" on A, and I do see the arp requests coming in. Once the boxes connected to L actively ping (or anything else) anything hooked up to either A or B, that destination can then reach that box as it then has the MAC of the box (so MAC addresses seem to be learned correctly on the Cisco switches). Doing a tcpdump on a Linux box hooked up to L showed me no ARP requests from behind A, so there must be SOMETHING keeping either A from forwarding the ARP requests, or L from accepting them on the trunk link. As the Linksys was just hooked up replacing a 3524, without any changes to the two 3560s, I wouldn't expect the Cisco switches to be causing this ... especially as there isn't much to the port config anyway...: interface GigabitEthernet0/26 switchport trunk encapsulation dot1q switchport mode trunk speed nonegotiate Storm Control and stuff is all disabled on the Linksys, can't really see anything else in the config that could/should cause this kind of problem ... Anybody have any suggestions? Tnx! -- They who would give up an essential liberty for temporary security, neiter deserve nor receives either -- B.Franklin _______________________________________________ cisco-nsp mailing list [email protected] https://puck.nether.net/mailman/listinfo/cisco-nsp archive at http://puck.nether.net/pipermail/cisco-nsp/
