North American Network Operators Group
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Re: weird BGP cisco-ism?

  • From: Ravi Chandra
  • Date: Fri Jul 11 04:05:35 1997 
> > add a default-metric under router bgp.. I think the source of the
> > route in the routing table is changing for some reason and the box is
> > conveying the metric as MED...
> > 
> > --ravi
> 
> Did that. It went from advertising it with an MED of 0 to an MED of 20 and
> back, to just readvertising it over and over with the fixed default MED
> I'd set (1).


This indicates that your flap is fixed.. the neighboring AS will look
at these advertisments as duplicate and discard it (and hence no
dampening). 

To avoid readvertising the same prefix, you might want to check if
there is any other dynamic protocol that is installing that prefix in
the routing table and removing it (could be a OSPF subnet...)


> 
> The sad thing is that until flap damping code was added, this sort of
> bug was masked... but now I have a few dozen customers totally offline.
> 


As soon as the reuse interval kicks in they should be fine..

--ravi


> -matthew
> 
>