[quagga-users 14828] Re: BGP flapping: BGP type 2 length 3300 is too large, attribute total length is 2309.

> Message: 2
> Date: Sat, 30 Sep 2017 20:49:57 +0200
> From: Kurt Jaeger <q-u-0ypjuhzD/[email protected]>
> To: Zdenek Janda <[email protected]>
> Cc: quagga-users-UOy77sIEA+cAd7ICUelF/[email protected]
> Subject: [quagga-users 14814] Re: BGP flapping: BGP type 2 length 3300
> 	is too large, attribute total length is 2309.
> Message-ID: <[email protected]>
> Content-Type: text/plain; charset=us-ascii
> 
> HI!
> 
> > after 3 years of operating quagga bgpd, i did have suddenly hit error
> > between two Quagga BGPD routers:
> > 
> > 2017/09/30 20:05:47 BGP: 185.120.68.25: BGP type 2 length 3300 is too
> > large, attribute total length is 2309.  attr_endp is 0x55b24ff1f323.
> > endp is 0x55b24ff1ef3c
> 
> Yes, we had the same problem this morning.
> 
> See the discussion around this mailthread
> 
>   https://lists.quagga.net/pipermail/quagga-users/2017-September/014836.html

please take a look at the following patch by Andreas Jaggi:

    https://lists.quagga.net/pipermail/quagga-dev/2017-September/033284.html

Since applying it, our routers have not been hit with this problem
again. If you must rely on distro packages, you may want to draw the
distro package maintainer's attention to this patch.

The workaround with as-path access-list restricting the number of as path
components as noted in
https://lists.quagga.net/pipermail/quagga-users/2017-September/014839.html
will only help the routers _behind_ the one applying this access-list.
A router receiving such a malformed AS path from outside will still show
this problem. 

Regards
Matthias Ferdinand