- Bird-users - Mailing Lists

[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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Re: [PATCH v5] Babel: Replace internal route selection by bird's nest
by nick 26 Oct '25

26 Oct '25

Hello, We're still waiting for any feedback on this useful patch. We've been running it in our mesh network with nearly 200 nodes. I'm also considering submitting it to the routing feed (cc @Toke), and I hope the patch will be adapted for BIRD 3 as well. For reference, here's the original post: https://bird.network.cz/pipermail/bird-users/2023-February/016705.html Tested-by: Nick Hainke <vincent(a)systemli.org> Best regards, Nick

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[PATCH] BGP: Do not start connect retry timer if connect immediately succeeds
by Ze Xia 18 Oct '25

18 Oct '25

BGP connect retry timer is unconditionally started in bgp_connect(), which will be stopped by bgp_send_open() in bgp_connected() with successful connection. However, if the sk_connect() in sk_open() immediately succeeds, this code path will be immediately called. This happens before the timer is even started, thus the timer will never be stopped again. Signed-off-by: Ze Xia <billxia135(a)gmail.com> --- proto/bgp/bgp.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/proto/bgp/bgp.c b/proto/bgp/bgp.c index ad51e626..6358afc6 100644 --- a/proto/bgp/bgp.c +++ b/proto/bgp/bgp.c @@ -1628,8 +1628,10 @@ bgp_connect(struct bgp_proto *p) /* Enter Connect state and start establishing c s->ao_keys_num = 0; s->ao_keys_init = NULL; - DBG("BGP: Waiting for connect success\n"); - bgp_start_timer(conn->connect_timer, p->cf->connect_retry_time); + if (s->type == SK_TCP_ACTIVE) { + DBG("BGP: Waiting for connect success\n"); + bgp_start_timer(p, conn->connect_timer, p->cf->connect_retry_time); + } return; err: -- 2.45.2

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Question: statistics column rejected vs. filtered
by Maiyun Zhang 17 Oct '25

17 Oct '25

Hello all, I am sorry if this is already documented somewhere. I have a question regarding the output of `birdc show protocol all xxx`: what is the difference between the "rejected" and the "filtered" columns? Regards, Maiyun Zhang (he/him)

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Syntax of 'show babel' commands?
by Chris Webb 16 Oct '25

16 Oct '25

I have a router with a simple babel protocol announced on an interface: protocol babel babel { interface "eth2" { next hop prefer ipv6; }; ipv4 { export where net ~ [0.0.0.0/0]; import none; }; ipv6 { export where net ~ [::/0]; import none; }; randomize router id; } bird> show proto babel Name Proto Table State Since Info babel Babel --- up 17:32:00.497 Out of interest, I tried the 'show babel' commands, but couldn't work out the syntax: bird> show babel ? show babel interfaces [<name>] ["<interface>"] Show information about Babel interfaces show babel neighbors [<name>] ["<interface>"] Show information about Babel neighbors show babel entries [<name>] Show information about Babel prefix entries show babel routes [<name>] Show information about Babel route entries bird> show babel interfaces "eth2" syntax error, unexpected CF_SYM_KNOWN bird> show babel interfaces babel syntax error, unexpected CF_SYM_KNOWN bird> show babel routes babel syntax error, unexpected CF_SYM_KNOWN What would be a correct argument to supply to these commands? In case it's relevant, I'm running 2.17.1 on Linux, which is the latest 2.x version on https://bird.network.cz/ https://bird.network.cz/download/ although I've just spotted there was a 2.17.2 announced on the mailing list in September. Best wishes, Chris.

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SRv6 support
by Sébastien PARISOT 15 Oct '25

15 Oct '25

Hello BIRD team, Is there interest for SRv6 support in BIRD? We have an internal fork with SRv6 L3VPN support that we have been using for several years in our network, we can upstream the patches. It is not a 100% complete support (at least the SID allocator is missing: we use static routes to bind the routes to a specific SID), but it is enough to act as a PE, there is BGP support and it installs remote SRv6 routes in the Linux kernel SRv6 using netlink. Please let me know what you think. If anyone would like to have a look, I attach the patches (for master branch) to implement SRv6 SID stack support in the nest and static protocol. Any comments are welcome. Example: protocol static { vpn4 { table vpntab4; }; route 10:42 10.0.0.0/24 via "eth0" srv6 fc::42; } bird> show route table vpntab4 Table vpntab4: 10:42 10.0.0.0/24 unicast [static1 14:17:42.184] * (200) dev eth0 srv6 <fc::42> I still have some clean-up work to do before I can share the rest of the patches (mainly netlink and bgp). Thanks. -- Sébastien

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L3VPN: Adding support for import/export target none and import target all
by Sébastien PARISOT 14 Oct '25

14 Oct '25

Hello BIRD team, This patch (for master branch) contains two commits for L3VPN protocol: - 0001: It adds support for "import/export target none" (or "[]" to specify an empty set, which is the same). For example it can be used when we do not want to import/export any route from/to the VRF, of if we prefer to set the RT it in filters (adding different RT for different IP prefixes for example). - 0002: It adds support for "import target all", ie all VPN routes are imported in the VRF IP table regardless of the RTs. Useful when we need to import any route or we want to have a more complex policy implemented in filters. Thanks! -- Sébastien

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