November 2025 - Bird-users

[EVPN] BIRD segfaults when I add interface to a bridge
by Tomáš Matuš 12 Nov '25

12 Nov '25

Hello BIRDs! And hello Ondřej. As a part of my thesis I've been toying with EVPN in BIRD on the oz-evpn branch and I managed to run into a segfault when I add ethernet interface into a bridge. I am using a couple fedora 42 VMs and I have this running in pnetlab but I hope virtualization is not a problem here. I narrowed it down to this very minimal bird.conf: ``` log stderr all; log "/var/log/bird.log" all; router id 10.10.10.3; ipv4 table master4; protocol device { scan time 10; }``` and a reproducer is basically what is in the README in [cf-evpn-bgp-tags](https://gitlab.nic.cz/labs/bird-tools/-/tree/master/netlab/cf-evpn-bgp-tags) test: ``` [root@debug ~]# ip link add name br0 type bridge vlan_filtering 1 [root@debug ~]# ip link add name vxlan0 type vxlan id 100 local 10.10.10.3 dstport 4789 nolearning [root@debug ~]# ip link set vxlan0 master br0[root@debug ~]# bridge link set dev vxlan0 learning off [root@debug ~]# ip link set dev eth1 master br0 [root@debug ~]# bird -fSegmentation fault (core dumped) ``` I spent some time debugging this, although I am not too familiar with netlink I hope my description will be useful :) Segfault happens in "sysdep/linux/netlink.c" because [this strcmp](https://gitlab.nic.cz/labs/bird/-/blob/oz-evpn/sysdep/linux/netlink.c?ref_type=heads#L1037) on line 1037 gets a NULL in the first parameter "kind" which seems expected based on that "kind" is set conditionally. Looking at the [array li](https://gitlab.nic.cz/labs/bird/-/blob/oz-evpn/sysdep/linux/netlink.c?ref_type=heads#L1030) and its size == 3 and into the "nl_parse_attrs" function I understand that you are only trying to get the first three (?) IFLA_INFO_x items which are IFLA_INFO_UNSPEC, IFLA_INFO_KIND, IFLA_INFO_DATA. The first "a->rta_type" that I see on my eth1 interface has a value 4 which is the IFLA_INFO_SLAVE_KIND and reading the data from it I indeed get "bridge" as a result. All of these get skipped by the first [continue](https://gitlab.nic.cz/labs/bird/-/blob/oz-evpn/sysdep/linux/netlink.c?ref_type=heads#L538) so "nl_parse_attrs" does not return anything useful. Is it possible that netlink is just not sending the data you need? Bug most likely comes from [66edbe43](https://gitlab.nic.cz/labs/bird/-/commit/66edbe43ce1fec8465577637c359d0294f580055) commit which is specific to the oz-evpn branch so other non-evpn branches are unaffected. I'm also attaching a patch which fixes it for me and I can have EVPN up and running. Thank you for your time and I hope you'll have a great day! Tomáš

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Question about MD5/auth warnings.
by Leo Vandewoestijne 11 Nov '25

11 Nov '25

Hello, On a router with several sessions I use "cascading" templates. Not all sessions have authentication, but those that do all default to MD5. When leaving the authentication option unset, you get warnings like: bird: /usr/local/etc/bird.conf:57:18: Missing authentication option, assuming MD5 But when setting 'authentication md5;' in my main template, then sessions without password will complain: bird: /usr/local/etc/bird.conf:56:28 MD5 authentication and password option should be used together /usr/local/etc/rc.d/bird: WARNING: failed to start bird In the past using a useless 'password "";' helped to simply surpress warnings, but not anymore. So now I have to add multiple templates to add 'authentication md5;' to sessions with authentication. Long story short, my question is: why can't you affirm 'authentication md5;' as main default, regardless wether sessions do or don't have a password? -- With kind regards, Met vriendelijke groet, Mit freundlichen Grüß, Leo Vandewoestijne <%2A%2A%2A(a)dns.company> <www.dns.company>

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Bird and cpu clock / cores.
by Mike Neo 06 Nov '25

06 Nov '25

Hi, What's more important for a bird, the clock speed of a single processor core or the number of physical cores? For example, which is the better choice: 8x2.2 GHz or 4x3.8 GHz Kind regards, Mike

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BIRD crashes on OSPF reconfiguration
by Nicolas Devos 03 Nov '25

03 Nov '25

Hello, I am here to report a crash encountered upon reconfiguration of bird. The crash is reproducible using the `birdc reconfigure soft` command. In this example I changed the OSPF link type (from pointopoint to broadcast). However, I have seen the crash with other reconfigurations as well. Below I entering the configurations, log and stack trace. This hopefully helps in debugging the issue. If more information is needed, let me know. I am happy to help where I can. The tested version is v3.1.4. ``` # bird -u bird -g bird -c /opt//bird/bird.conf -d bird: 2025-10-28 12:37:48.107 [0001] Chosen router ID 10.89.112.123 according to interface enp6s0 bird: 2025-10-28 12:37:48.107 [0001] Started bird: 2025-10-28 12:37:50.621 [0001] Reconfiguring bird: 2025-10-28 12:37:50.621 [0001] Adding protocol ospf1 bird: 2025-10-28 12:37:50.621 [0001] Reconfigured bird: 2025-10-28 12:37:53.885 [0001] Reconfiguring bird: 2025-10-28 12:37:53.886 [0001] ospf1: Restarting interface enp11s0.3676 (172.21.8.0/28) in area 0.0.0.1 bird: 2025-10-28 12:37:53.886 [0001] Trying to lock in a bad order: 00007ffed0528670 00007f9a66c1a3b8 Aborted (core dumped) ``` ``` # birdc 'configure soft "/tmp/ospf/ospf-2.conf"' BIRD 3.1.4 ready. Reading configuration from /tmp/ospf/ospf-2.conf Reconfigured # birdc 'configure soft "/tmp/ospf/ospf-1.conf"' BIRD 3.1.4 ready. Connection closed by server ``` ``` # cat /tmp/ospf/ospf-1.conf router id 10.89.112.123; protocol device {} protocol kernel { learn; scan time 20; ipv4 {}; } protocol ospf v2 { area 1 { interface "enp11s0.3676" { dead 40; type broadcast; }; }; } ``` ``` # cat /tmp/ospf/ospf-2.conf router id 10.89.112.123; protocol device {} protocol kernel { learn; scan time 20; ipv4 {}; } protocol ospf v2 { area 1 { interface "enp11s0.3676" { dead 40; type pointopoint; }; }; } ``` ``` Thread 1 "bird" received signal SIGABRT, Aborted. 0x00007ffff7c8bedc in __pthread_kill_implementation () from /lib64/libc.so.6 (gdb) bt #0 0x00007ffff7c8bedc in __pthread_kill_implementation () from /lib64/libc.so.6 #1 0x00007ffff7c3eb46 in raise () from /lib64/libc.so.6 #2 0x00007ffff7c28833 in abort () from /lib64/libc.so.6 #3 0x0000555555636e1f in bug () #4 0x0000555555638b83 in do_lock () #5 0x00005555555969f9 in olock_free.lto_priv () #6 0x000055555558b85a in pool_free () #7 0x000055555559712f in rfree.part () #8 0x0000555555600265 in ospf_reconfigure.lto_priv () #9 0x00005555555a7581 in protos_do_commit.lto_priv () #10 0x00005555555786e4 in config_do_commit () #11 0x0000555555579bf3 in config_commit () #12 0x000055555563dc12 in cmd_reconfig () #13 0x0000555555654f6a in cf_parse.isra () #14 0x0000555555571e12 in cli_parse () #15 0x000055555559e6d9 in cli_command () #16 0x000055555559e93b in cli_event.lto_priv () #17 0x000055555558d953 in ev_run_list_limited () #18 0x000055555556bf4e in main () ``` Kind regards, Nicolas This message and any attachment are confidential and may be privileged or otherwise protected from disclosure. If you are not the intended recipient, please notify the sender immediately and delete this message and any attachment from your system. Do not copy them or disclose the contents to any other person.

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