carrier comparison

Faisal Imtiaz faisal at
Fri Feb 7 14:49:09 UTC 2014

Based on my understanding on BFD, it will not help you... BFD will detect the direct connected port being down quicker and force the BGP session down, (faster than the time  BGP session timers take to determine something is broken)

This is the common issue / challenge in how to determine up-stream path outage and then doing appropriate route engineering on an automatic basis.

Maybe a SLA monitor type scripting/configuration be useful in your case.

Faisal Imtiaz
Snappy Internet & Telecom
7266 SW 48 Street
Miami, FL 33155
Tel: 305 663 5518 x 232

Help-desk: (305)663-5518 Option 2 or Email: Support at 

----- Original Message -----
> From: "Olivier Benghozi" <olivier.benghozi at>
> To: nanog at
> Sent: Friday, February 7, 2014 5:25:53 AM
> Subject: Re: carrier comparison
> Hi Faisal,
> > You might have to deploy some other means of (script ?) to bring your BGP
> > session down from the 'broken' Service Provider.
> > 
> > To the best of my knowledge, BGP does not have any mechanism to determine
> > broken connectivity upstream past the router you are BGP session is up
> > with.
> Well, technically there's BFD that might do the trick. But of course it won't
> be available; it's not usually, so specially with Cogent... :)
> But maybe its link was just overloaded in fact.
> --
> Olivier

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