I have two 6850's running 6.3.1 that have been experiencing crashes frequently. The crashes happen when the port going to the default gateway loses link. For example, if the default gateway in the routing table is connected to port 1/17, and port 1/17 goes down, the switch crashes.
AL tech support has analyzed some of the Crash.pmd files I have sent them, and they say that the cause of the crash was excessive traffic. So, I am thinking route loop. I can't find any source of a loop in the network though. I am using OSPF throughout my network, but I have a few places with static routes carefully defined.
Is there a way that I can see what the new default route would be if the current one was lost? With EIGRP, you ccould see the "feasible successor" route. Is there a way to look at the OSPF topology on a AOS router to see what the next-best default route is?
Thanks,
-Mark Williams
6850 Crash whenever default gateway goes down
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frank
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Hi Mark,
Can you give more detail about your configuration ?
A loop would be if you have link between the 2 6850, and each of the 6850 then connected to your default gateway. If this is the case, did you activate spanning tree ?
if not, did you do a VERY BASIC test ? Unlink the 6850, and unplug your port 1/17. Does the switch goes down at this point ? I hope not
If yes, push on TAC SUPPORT and let us know your findings !
Can you give more detail about your configuration ?
A loop would be if you have link between the 2 6850, and each of the 6850 then connected to your default gateway. If this is the case, did you activate spanning tree ?
if not, did you do a VERY BASIC test ? Unlink the 6850, and unplug your port 1/17. Does the switch goes down at this point ? I hope not
If yes, push on TAC SUPPORT and let us know your findings !Code Free Or Die
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cedric1
Hello
Thanks Frank for these info.
You can use this command : show ip router database
you will see inactive route and next best route.
But simple test is to lunch traceroute command on your switch and make interface 1/17 admin down and see what happen.
With tracert you will immediately see if you ha loop via TTL .
Cedric
Thanks Frank for these info.
You can use this command : show ip router database
you will see inactive route and next best route.
But simple test is to lunch traceroute command on your switch and make interface 1/17 admin down and see what happen.
With tracert you will immediately see if you ha loop via TTL .
Cedric
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benny
How many other ports are connected?
Did you try to debug with DRCLOG? If not, I'd like to recommend that since any change in OSPF will be on console (or your SSH session) then until the crash happens.
Make sure to log the output to a text-file for later reviewing as it is going to be a lot of data.
-> show drclog ospf
-> debug drclog ?
-benny
Did you try to debug with DRCLOG? If not, I'd like to recommend that since any change in OSPF will be on console (or your SSH session) then until the crash happens.
Make sure to log the output to a text-file for later reviewing as it is going to be a lot of data.
-> show drclog ospf
-> debug drclog ?
-benny
