[c-nsp] MPLS "Tag Control" process - what does this do?

[Rodney Dunn]

> >
> >Yeah..after you reload look at the free memory. If it's low right after
> >a reload you don't have enough memory. If it decreases over time you have
> >a leak that needs to be debugged.
> 
> It hasn't been reloaded yet, but:
> 
> 199city-rB2-dcs01#show mem summary
>                 Head    Total(b)     Used(b)     Free(b)   Lowest(b)  
>                 Largest(b)
> Processor     CA17A0    53854304     8625208    45229096       39756     
> 2489720
>       I/O   80000000     8388608     3832080     4556528     4551892     
>       4544080


Ruh oh...  You ate up 45+M of transient memory. Notice how the lowest
was 39k. I bet that box got the BGP dumped in it somehow and
started sending labels for those prefixes. And the 72xx was getting
them and trying to process them from the TDP/LDP peer.

Like you said in the other response to Oli. You need to find out
what prefixes those were and why the upstreams allocated and sent
labels for them. :)

Rodney

> 
> >>The reason I am bringing this up is that I'm considering if the problem 
> >>may not have been directly caused by this 7200, but may be caused by some 
> >>other external factor.  The only thing which strikes me as a possibility 
> >>is that someone or something flooded/redistributed an entire BGP feed 
> >>into OSPF.  Does that sound like a possibility?
> >
> >Yep. Been there seen that more than once. :)
> >
> >Without snapshots of the routing table it's hard to say.
> 
> I know :-(
> 
> >If you didn't reboot this 72xx was does the loweest show in 'sh mem stat'?
> 
> 370flinders-r200.32-pe01#show mem statistics
>                 Head    Total(b)     Used(b)     Free(b)   Lowest(b)  
>                 Largest(b)
> Processor   63739FC0   948723776   167593200   781130576   623354028   
> 278449760
>       I/O    C000000    67108864     6060664    61048200    59514824    
>       58316348
> 370flinders-r200.32-pe01#
> 
> >That would show you if you ran it really low at some point.
> >
> >>Still doesn't answer quite why the 7200 was chewing so much cpu though 
> >><scratches head>.
> >
> >Got a ton of routes or the routes were churning a lot. Or you got a slew
> >of label advertisements from the tdp/ldp peers most likely.
> 
> Looks like all the OSPF routes are only 7h:50m old.  That's about the time 
> it was all going on.  All the exterior/BGP routes are relatively old, all 
> some days old.
> 
> Looking inside one of the VRFs I can see that most, but not all, routes are 
> of about that age too.
> 
> Reuben