[Fwd: [OCCAID] Advisory: Extended Community bit crashing Quagga and Zebra BGPd]

[Roger Jorgensen]

On Tue, 20 Dec 2005, Andrew Alston wrote:
<snip>
> 
> It appears Extended Community bit used for MPLS VPN, when improperly set,
> crashes Quagga version 0.96.5, Zebra versions 0.93 through 0.94 running on
> FreeBSD 5.x and 6.0 platforms.

think you maybe can add Linux to that OS list, have had some strange 
crashed on my bgpd/zebra the last week without any reasons, upgraded to 
the newest quagga and have been stable since.


> APC4 release is not affected, running on OCCAID backbone, however there are
> many downstream BGP sessions running off of Quagga 0.96.5 going down a lot
> lately, which lead us to find out what prefix is crashing them.
> 
> It seems it is being received from AS5430 peering, with unknown Extended
> Community, which happens to segfault bunch of bgpd's:
> 
>   5430 25538
>     2001:4830:1::3 (metric 1980) from 2001:4830:1::3 (65.126.230.17)
>       Origin IGP, metric 0, localpref 200, valid, internal, best
>       Community: 30071:58012
>       Extended Community: Unknown
> 
> Courtesy of Andrew Alston from TENET:
> 
> (gdb) bt
> #0  0x2818237b in kill () from /lib/libc.so.5
> #1  0x28177422 in raise () from /lib/libc.so.5
> #2  0x281e9c1b in abort () from /lib/libc.so.5
> #3  0x2818d5b9 in ldexp () from /lib/libc.so.5
> #4  0x2818d5fd in ldexp () from /lib/libc.so.5
> #5  0x2818e163 in ldexp () from /lib/libc.so.5
> #6  0x2818e743 in ldexp () from /lib/libc.so.5
> #7  0x2818e874 in free () from /lib/libc.so.5
> #8  0x0807102a in ecommunity_free (ecom=0x832a710) at
>                   bgp_ecommunity.c:49
> #9  0x0805596b in bgp_attr_unintern (attr=0x832c480) at
>                   bgp_attr.c:551
> #10 0x0806abbd in bgp_update_packet (peer=0x8251000,
>                   afi=2, safi=1 '\001') at bgp_packet.c:224
> #11 0x0806b361 in bgp_write_packet (peer=0x8251000) at
>                   bgp_packet.c:507
> #12 0x0806b45b in bgp_write (thread=0x0) at
> #13 0x0808c705 in thread_call (thread=0xbfbfecfc) at
>                   thread.c:850
> #14 0x0804a2ae in main (argc=4, argv=0xbfbfedcc) at
>                   bgp_main.c:308
> 
> 
> Until we can reproduce the problem here at the lab and get this resolved,
> for the purpose of ensuring stable network operations for our customers, we
> are temporarily filtering all Extended Communities bits entering our
> network.
> 
> Thanks,
> 
> James Jun
> IP Infrastructure & Technology Services
> TowardEX Technologies, Inc.
> WWW: http://www.towardex.com
> Email: james at towardex.com
> Office: +1 (617) 459-4051 Ext. 179
> Mobile: +1 (978) 394-2867
> 
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-- 


------------------------------
Roger Jorgensen              |
rogerj at stud.cs.uit.no        | - IPv6 is The Key!
http://www.jorgensen.no      | roger at jorgensen.no
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