[185537] in North American Network Operators' Group
Re: BGP hold timer on IX LAN
daemon@ATHENA.MIT.EDU (Colin Johnston)
Tue Oct 27 04:42:44 2015
X-Original-To: nanog@nanog.org
In-Reply-To: <562F33B5.7090005@foobar.org>
From: Colin Johnston <colinj@gt86car.org.uk>
Date: Tue, 27 Oct 2015 08:42:36 +0000
To: Nick Hilliard <nick@foobar.org>
Cc: North American Network Operators' Group <nanog@nanog.org>
Errors-To: nanog-bounces@nanog.org
low bgp timers usually done to allow faster hsrp failover result
colin
Sent from my iPhone
> On 27 Oct 2015, at 08:20, Nick Hilliard <nick@foobar.org> wrote:
>
>> On 27/10/2015 08:31, marcel.duregards@yahoo.fr wrote:
>> I'm asking because we see more and more peering partners which force the
>> hold timer to a lower value, and when BGP negotiate the timer, the lowest
>> hold timer is the winner.
>
> You need to be careful with this. On larger IXPs, there will be a wide
> variety of kit with different capabilities, which will usually work well in
> most circumstances, but which may not have enough cpu power to handle edge
> cases like e.g. ixp maintenance or flaps when you get large amounts of bgp
> activity. A low bgp timer might be fine for, say an asr9k or an mx960 with
> the latest RE/RSP, but would be actively harmful if one of your peers is
> using an mx80 or a sup720.
>
> Nick
>
>
