On Sun, Mar 23, 2014 at 02:50:02PM +0100, Job Snijders wrote:
Hi all,
It seems it is possible to create a situation like this:
Hold timer: 46/60 Keepalive timer: 56/80
Note the hold timer versus keepalive timer! This happens when the other side (in this case a JunOS box) configures a hold-time of 60 seconds. This results in endless session flapping because the BIRD box will not send Keepalives in a timely fashion.
There is the BIRD configuration:
template bgp peers { local as 199036; multihop; hold time 240; startup hold time 240; connect retry time 120; keepalive time 80;
^^^^^^^^^^^^^^^^^
While it is not strong RFC vocabulary, it is my interpretation that it would be more robust if the Keepalive Timer defaults to Hold Timer divided by three, when the Hold Timer is smaller than 3 times the configured Keepalive Timer.
Is this expected behaviour or a bug?
It is expected behavior - if you explicitly specify keepalive time, then you override the default (which is 1/3 of agreed hold time) even if the specified value is nonsensical w.r.t. agreed hold time. -- Elen sila lumenn' omentielvo Ondrej 'SanTiago' Zajicek (email: santiago@crfreenet.org) OpenPGP encrypted e-mails preferred (KeyID 0x11DEADC3, wwwkeys.pgp.net) "To err is human -- to blame it on a computer is even more so."