[c-nsp] Cisco 7206VXR OSPF

[Jason Berenson]

Ben,

We have 3 7206's used as edge routers.  PA-MC-T3 in from our DAX and 
ethernet out to our transport.  So there are a few adjacencies along 
with iBGP and eBGP.  It seems like the router that goes down (flaps 
OSPF/BGP instance 1) is the only one that takes a hit out of all of them 
connected to the switches.

I'm leaning away from thinking this is an ethernet issue, but I 
definitely could be wrong.  Are there any helpful outputs I could include?

Thanks,
Jason

Ben Steele wrote:
> Are any other hosts affected off the switch during this period aswell?
>
> Ben
> On 13/03/2008, at 8:05 AM, Jason Berenson wrote:
>
>> Rodney,
>>
>> They connect back to a cisco switch.  No errors anywhere along the
>> ethernet and no packet loss.  It also only flapped 3 times yesterday and
>> 2 times 5 days ago, so it's not a constant flap.
>>
>> It hasn't flapped yet today, so I'll turn on debugging and setup a snoop
>> and write back when I have something.  About the debugging - will
>> turning on the commands suggested (ospf event or ospf adj)  have an
>> averse affect on the routers performance?
>>
>> Thanks,
>> Jason
>>
>> Rodney Dunn wrote:
>>> What is the physical topology?
>>>
>>> Is it back to back ethernet?
>>>
>>> On Wed, Mar 12, 2008 at 11:37:42AM -0400, Jason Berenson wrote:
>>>
>>>> Joe,
>>>>
>>>> I checked the neighbors too.  I do see the session flap there but 
>>>> again,
>>>> no errors on the ethernet and nothing really obvious as to why it
>>>> flapped.  This just started in the past few days.  I do see some CPU
>>>> spikes to 100% but it doesn't correlate exactly to when the flap 
>>>> occurred.
>>>>
>>>> -Jason
>>>>
>>>> Joe Freeman wrote:
>>>>
>>>>> If OSPF is flapping, you should see it on the neighbor attached to
>>>>> that interface as well, so you might look there for issues.
>>>>>
>>>>> Joe
>>>>>
>>>>> On 3/12/08, *Jason Berenson* <jason at pins.net <mailto:jason at pins.net>>
>>>>> wrote:
>>>>>
>>>>>   Rodney,
>>>>>
>>>>>   The interface is clean.  No errors/drops at all.  I think I'll 
>>>>> have to
>>>>>   snoop that segment like you suggested and wait for it to flap 
>>>>> again.
>>>>>
>>>>>   Thanks,
>>>>>
>>>>>   Jason
>>>>>
>>>>>
>>>>>   Rodney Dunn wrote:
>>>>>> Look for intput drops on the 'sh int'.
>>>>>>
>>>>>> If you don't see any you probably need a sniffer trace on the
>>>>>> ethernet segment.
>>>>>>
>>>>>> On Tue, Mar 11, 2008 at 03:53:30PM -0400, Jason Berenson wrote:
>>>>>>
>>>>>>> Greetings,
>>>>>>>
>>>>>>> We have a few 7206's running OSPF/BGP for routing.  All of the
>>>>>   routers
>>>>>>> are fine except for one - I noticed a few times in the past
>>>>>   week where
>>>>>>> OSPF/BGP flapped and came back right away.
>>>>>>>
>>>>>>> I checked CPU and noticed it peaked in the past hour but that
>>>>>   doesn't
>>>>>>> really correlate to the time the routing sessions flapped.  I also
>>>>>>> didn't see the ethernet connection go down and I don't see any
>>>>>   errors on
>>>>>>> either side of the ethernet.
>>>>>>>
>>>>>>> If there are any outputs anyone would expect please let me know
>>>>>   and I'll
>>>>>>> promptly reply.  This is the first time I'm faced with a
>>>>>   problem like
>>>>>>> this so I'm not really sure where to look other then the things
>>>>>   I've
>>>>>>> already tried.
>>>>>>>
>>>>>>> Much thanks in advance,
>>>>>>> Jason Berenson
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