bfd-like mechanism for LANPHY connections between providers

Richard A Steenbergen ras at
Wed Mar 16 12:03:43 CDT 2011

On Wed, Mar 16, 2011 at 06:56:28PM +0200, Tassos Chatzithomaoglou wrote:
> Are there any transit providers out there that accept using the BFD (or 
> any other similar) mechanism for eBGP peerings?
> If no, how do you solve the issue with the physical interface state when 
> LANPHY connections are used?
> Anyone messing with the BGP timers? If yes, what about multiple LAN 
> connections with a single BGP peering?

Well first off LAN PHY has a perfectly useful link state. That's pretty 
much the ONLY thing it has in the way of native OAM, but it does have 
that, and that's normally good enough to bring down your EBGP session 
quickly. Personally I find the risk of false positives when speaking to 
other people's random bad BGP implementations to be too great if you go 
much below 30 sec hold timers (and sadly, even 30 secs is too low for 
some people). We (nLayer) are still waiting for our first customer to 
request BFD, we'd be happy to offer it (with reasonable timer values of 
course). :)

Richard A Steenbergen <ras at>
GPG Key ID: 0xF8B12CBC (7535 7F59 8204 ED1F CC1C 53AF 4C41 5ECA F8B1 2CBC)

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