BIRD - iBGP between RS over IPv6 lead to crash (segfault)
Hello, We're using BIRD 1.6.4 as Route Server. Recently we have decided to establish an internal BGP session between both RS over IPv6 But when we added our config in BIRD then it has crashed immediately with the following error: [35878512.553496] bird6[2545]: segfault at 0 ip 000055f60242c331 sp 00007ffd43689460 error 4 in bird6[55f60240a000+86000] At same time we have several working iBGP session between RS <> Routers ( not RS ) from a long time and everything works fine with them. Here is the example config that crashed the system. Note: The original ASN has been replaced with 1234 in the example. table T1234 protocol pipe P1234 from iBGP_PIPES { peer table T1234; export all; } protocol bgp R100 { description "iBGP_RS1"; source address 2001:67c:29f0::A:1:234:200; neighbor 2001:67c:29f0::A:1:234:100 as 1234; local as myas; prefer older on; missing lladdr ignore; import none; export none; passive off; table T1234; add paths on; direct; } Another more strange: 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. Here is the config: template bgp iBGP { local as myas; import all; export all; import limit 21000; passive on; prefer older on; missing lladdr ignore; } protocol bgp R1234x100 from iBGP { description "iBGP_RS1"; neighbor 2001:67c:29f0::A:1:234:100 as 1234; import all; export all; passive off; table T1234; # add paths on; direct; import limit 4000000; } Here is the logs from both side: Jul 7 11:52:09 rs1 bird6: R1234x4: Connecting to 2001:67c:29f0:0:a:1:234:4 from local address 2001:67c:29f0:0:a:1:234:100 2021-07-07 11:53:56 <TRACE> R1234x100: Connecting to 2001:67c:29f0:0:a:1:1234:100 from local address 2001:67c:29f0:0:a:1:234:4 Upper logs messages are repeating several times but iBGP was not establish.No any other logs persist in the logs message regarding this session establishment attempt. Could someone BIRD developer to suggest some solution for fixing this issue? We highly appreciate any kind of support. I had doubt that "add paths on" command would leading to this crashes but I commented it and after reloading the system crashed again. At same time this setup iBGP between the same RS over IPv4 works fine. Thanks in advance! Best~ Javor Kliachev Senior Engineer IP Services office: +359 2 974 33 11 mobile: +359 885 98 84 95 [ http://www.neterra.net/ | www.neterra.net ] [ https://bg.linkedin.com/pub/javor-kliachev/11/b46/843 | ]
On Fri, Jul 09, 2021 at 11:43:53AM +0300, Javor Kliachev wrote:
Hello,
We're using BIRD 1.6.4 as Route Server.
Recently we have decided to establish an internal BGP session between both RS over IPv6
But when we added our config in BIRD then it has crashed immediately with the following error: [35878512.553496] bird6[2545]: segfault at 0 ip 000055f60242c331 sp 00007ffd43689460 error 4 in bird6[55f60240a000+86000] Another more strange:
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.
...
Could someone BIRD developer to suggest some solution for fixing this issue? We highly appreciate any kind of support.
Hello Well, first upgrade and try latest legacy version (1.6.8). Version 1.6.4 is too old and not worth to us to check whether it was already fixed or not. -- 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."
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 RS1 output: # birdc6 show proto BIRD 1.6.8 ready. name proto table state since info device1 Device master up 2021-07-20 10:50:21 P1234 Pipe master up 2021-07-20 10:50:21 => T1234 R1234x5 BGP T1234 start 2021-07-20 10:58:33 Connect direct1 Direct master down 2021-07-20 11:09:51 kernel1 Kernel master down 2021-07-20 11:09:51 # cat AS1234 table T1234 protocol pipe P1234 from iBGP_PIPES { description "RS"; peer table T1234; export all; } protocol bgp R1234x5 { description "iBGP_RS2"; source address 2001:67c:29f0::A:1:234:4; neighbor 2001:67c:29f0::A:1:234:5 as 1234; local as myas; prefer older on; missing lladdr ignore; import none; export none; passive off; table T1234; # add paths on; # direct; } =============================================================================== RS2 output: # birdc6 show proto BIRD 1.6.8 ready. name proto table state since info device1 Device master up 2021-07-20 10:52:23 P1234 Pipe master up 2021-07-20 10:52:23 => T1234 R1234x4 BGP T1234 start 2021-07-20 10:58:46 Connect direct1 Direct master down 2021-07-20 11:09:21 kernel1 Kernel master down 2021-07-20 11:09:21 # cat AS1234 table T1234 protocol pipe P1234 from iBGP_PIPES { description "RS"; peer table T1234; export all; } protocol bgp R1234x4 { description "iBGP_RS1"; source address 2001:67c:29f0::A:1:234:5; neighbor 2001:67c:29f0::A:1:234:4 as 1234; local as myas; prefer older on; missing lladdr ignore; import none; export none; passive off; table T1234; # add paths on; # direct; } 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. I appreciate any kind of help. Best~ Javor Kliachev Senior Engineer IP Services office: +359 2 974 33 11 mobile: +359 885 98 84 95 [ http://www.neterra.net/ | www.neterra.net ] [ https://bg.linkedin.com/pub/javor-kliachev/11/b46/843 | ] From: "Ondrej Zajicek" <santiago@crfreenet.org> To: "Javor Kliachev" <jkliachev@neterra.net> Cc: "bird-users" <bird-users@network.cz>, "inmt-ip" <inmt-ip@neterra.net> Sent: Friday, 9 July, 2021 16:33:20 Subject: Re: BIRD - iBGP between RS over IPv6 lead to crash (segfault) On Fri, Jul 09, 2021 at 11:43:53AM +0300, Javor Kliachev wrote: Hello, We're using BIRD 1.6.4 as Route Server. Recently we have decided to establish an internal BGP session between both RS over IPv6 But when we added our config in BIRD then it has crashed immediately with the following error: [35878512.553496] bird6[2545]: segfault at 0 ip 000055f60242c331 sp 00007ffd43689460 error 4 in bird6[55f60240a000+86000] Another more strange: 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. ... Could someone BIRD developer to suggest some solution for fixing this issue? We highly appreciate any kind of support. Hello Well, first upgrade and try latest legacy version (1.6.8). Version 1.6.4 is too old and not worth to us to check whether it was already fixed or not. -- 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."
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@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."
Hello Ondrej, Thank you very much for the provided support. The issue with not establishment of iBGP between RS-RS over IPv6 has been caused by wrong FW config. Thanks once again and have a nice day! Best~ Javor Kliachev Senior Engineer IP Services office: +359 2 974 33 11 mobile: +359 885 98 84 95 [ http://www.neterra.net/ | www.neterra.net ] [ https://bg.linkedin.com/pub/javor-kliachev/11/b46/843 | ] ----- Original Message ----- From: "Ondrej Zajicek" <santiago@crfreenet.org> To: "Javor Kliachev" <jkliachev@neterra.net> Cc: "bird-users" <bird-users@network.cz>, "inmt-ip" <inmt-ip@neterra.net> Sent: Friday, 23 July, 2021 18:23:08 Subject: Re: BIRD - iBGP between RS over IPv6 lead to crash (segfault) 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@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."
participants (2)
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Javor Kliachev -
Ondrej Zajicek