BIRD - iBGP between RS over IPv6 lead to crash (segfault)

[Ondrej Zajicek]

On Tue, Jul 20, 2021 at 01:41:06PM +0300, Javor Kliachev wrote:
> Hello Ondrej, 
> 
> Many thanks for the advise. 
> 
> We have upgraded BIRD to the latest 1.6.8 version. 
> In this version seems the crash issue is resolved but the second issue with 
> - iBGP between RS-RS over IPv6 still exists. This BGP session is not able to establish yet. 
> 
> In my LAB I have successfully replicated the issue. Both Route Servers are on BIRD with latest version 1.6.8. They have the following IPv6 addresses configured: 
> 
> RS1 IPv6 - 2001:67c:29f0::A:1:234:4 
> RS2 IPv6 - 2001:67c:29f0::A:1:234:5 
> 
> Here is the config fo each RS 
> 
> Seems the issue happens when remote peer is also BIRD. When remote peer is router ( Cisco, Juniper, Quagga etc... ) the session is successfully established. 
> On IPv4 iBGP between both RS works fine. So the issue related only with IPv6 stack. 
> 
> Initially before the crash we have added the following config below and RS was stable but session was not able to establish. 
> We have made a capture of the traffic during the attempt of session establishment and seems TCP handshake works but then not procced futher. 

Hello

Cannot replicate that, works for me. Do you have the problem with both
direct / multihop mode? Can you send me the capture? If you enable
'debug all' for sessions, what is in logs?

-- 
Elen sila lumenn' omentielvo

Ondrej 'Santiago' Zajicek (email: santiago at crfreenet.org)
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"To err is human -- to blame it on a computer is even more so."