7206 ATM OC3 Lane client with Ping drops

[iwearing]

Hi there,

2 x 7206 OC3 lane modules. Lane clients Register with Les/Bus on Nortel Centillion 100.

HSRP configured and working between Lane modules. However the Centillion supports dircetly connected Token Ring Devices.

When I run a continuous Ping from a Token Ring attached Cisco Router, to either of the 7206 OC3 Lane modules, I receive 11 successful pings followed by 1 drop. This is consistent, 11 replies a 1 fail.

Pings from Token Ring attached Pcs to the Lane modules are fine.

Any ideas would be appreciated.

Regards

Ian.

[carenas123]

As you said from Token ring attached PC's you are not getting any failures, the reason might be the longer timeout value for eg it is 4 sec for XP compare to 2 sec for a cisco router. I hope the other router is giving all replies but the one which is delayed just more than 2 sec also, you are seeing that one lost. Pls check with "debug ip icmp" at both ends of both ping requests and replies. And in another way, just use extended ping on cisco router and increase the timeout value say 3 sec, you won't see any drops.

[iwearing]

Thanks for the reply.

I eventually replaced the Nortel ATM MCP Module wjich fixed the originall fault. However I now have ATM INterface reliability issues.

ATM1/0 is up, line protocol is up

Hardware is ENHANCED ATM PA

MTU 4490 bytes, sub MTU 4470, BW 149760 Kbit, DLY 80 usec,

reliability 245/255, txload 1/255, rxload 1/255

Input queue: 1/75/31/0 (size/max/drops/flushes); Total output drops: 0

2009 output errors, 0 collisions, 0 interface resets

The Cisco PA has been replaced, Fiber cables replaced and the Nortel ATM Port changed. Symptoms are still the same.

Any ideas

Regards

Ian.