bird spawning huge amount of BGP traffic

[Ondrej Zajicek]

On Thu, Feb 19, 2015 at 04:55:21PM +0100, Simon Szustkowski wrote:
> Hi,
> 
> i am participating in a virtual network which is created for computer
> enthusiasts to gain knowledge about advanced routing protocols and stuff. It
> is called the DN42 (http://dn42.net).
> 
> Currently i am establishing BGP sessions with the help of quagga, but since
> it is quite bloated for my small setup, i would like to migrate to bird.
> 
> I have configured bird4 with the example config provided in the DN42 wiki
> (https://dn42.net/howto/Bird) (sorry about the HTML entities). The result
> is: Bird populates my routing table with all the correct routes, but spawns
> very huge amounts of BGP traffic. I ran it overnight accidentally, and it
> spawned over 70GB traffic on some interfaces, so these particular peers
> closed their VPN tunnels to me, which is understandable.
> I have created a minimal config by myself, which has the same result.
> However, peering with quagga works as expected, with all routes and little
> traffic.

Hi

The likely cause of the problem is that some peer flapped by some routes
and these were propagated by your router to other neighbors. BIRD does not
implement minimal interval (MRAI) to counteract this, Quagga has it
(which limits flapping and therefore you don't see the problem here).

Solution would be to log routes  ( debug protocols { routes }; ) to see
which BGP neighbor and which routes caused the problem and either not
peer with it or filter problematic routes.

-- 
Elen sila lumenn' omentielvo

Ondrej 'Santiago' Zajicek (email: santiago at 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."
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 181 bytes
Desc: Digital signature
URL: <http://trubka.network.cz/pipermail/bird-users/attachments/20150223/ae4c9a5c/attachment.asc>