September 2022 - Bird-users

[PATCH] Bus error on ARMv7 when using OSPF
by Matthew Reeve 18 Dec '24

18 Dec '24

Hi, when using bird 2.0.8 on openwrt 21.02 (and other versions) on a Netgear R7800 router, if the OSPF protocol is used, either v2 or v3, bird immediately crashes on startup with: Fri Jun 11 14:41:11 2021 daemon.info bird: Started Fri Jun 11 14:41:11 2021 kern.err kernel: [ 3500.853248] Alignment trap: not handling instruction f44c0a1f at [<00035848>] Fri Jun 11 14:41:11 2021 kern.alert kernel: [ 3500.853283] 8<--- cut here --- Fri Jun 11 14:41:11 2021 kern.alert kernel: [ 3500.859363] Unhandled fault: alignment exception (0x801) at 0x007e0624 Fri Jun 11 14:41:11 2021 kern.alert kernel: [ 3500.862443] pgd = 0bbef4fd Fri Jun 11 14:41:11 2021 kern.alert kernel: [ 3500.868821] [007e0624] *pgd=5d6ca835, *pte=5c40b75f, *ppte=5c40bc7f This router uses an ARMv7 processor and the issue seems to be to do with memory alignment issues. I've debugged it and traced it to an access to the top_hash_entry struct. I've found that if I add the PACKED macro to the struct definition then it fixes the problem, as per this patch: --- a/proto/ospf/topology.h +++ b/proto/ospf/topology.h @@ -41,7 +41,7 @@ struct top_hash_entry u8 mode; /* LSA generated during RT calculation (LSA_RTCALC or LSA_STALE)*/ u8 nhs_reuse; /* Whether nhs nodes can be reused during merging. See a note in rt.c:add_cand() */ -}; +} PACKED; /* Prevents ospf_hash_find() to ignore the entry, for p->lsrqh and p->lsrth */ Thanks.

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logging via udp
by Alexander Zubkov 13 Dec '23

13 Dec '23

Hello, Made some dirty patch for myself to allow bird to send logs via udp. But it may be useful not only for me, so posting it here. It could be useful when server experiencing high IO-load. As syslog and file operations in bird are blocking, it can be blocked on writing to it for indefinite time, which could lead to various problems like protocol timeouts. So udp logging comes in handy here. The tradeoff is that we can miss some logs if they are not processed in time. You can specify udp log destination like that: log udp [host IP|"hostname"] [port NUMBER|"portname"] ... By default it uses destination ip 127.0.0.1 and port 514. There are some constraints like not much error handling. And this destination replaces file destination, i.e. you can not use those simultaneously and it may leak descriptors and some memory probably if both are specified. It also makes a new socket every time configuration is reloaded even if there is no change in options, but this is not a great deal.

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BIRD show bgp summary for cli
by Roman Bulakh 14 Jun '23

14 Jun '23

Hi, we use BIRD in our environment, and it would be very nice to have some command like `show bgp summary` in juniper. This command show information about peer IP, peer AS, last update, prefixes received/best/exported and last state. Example: bird> show bgp summary Peer AS Last state change Prfx rcvd/best/export State X.X.X.X asXXXX 2021-01-27 6786/6785/109000 Established Y.Y.Y.Y asYYYY 2020-12-16 0/0/0 Passive BGP Error: Hold timer expired The are patch created for BIRD 1.3.4 and 1.3.6, but it would be good to have this in upstream software, without rebuilding and patching. as I understand it, no functionality should be affected by these changes, this is only a visual update for cli. Old patches describes at pages: https://marc.info/?l=bird-users&m=132155489919052&w=2 http://trubka.network.cz/pipermail/bird-users/attachments/20120228/a1499be7… https://bird-users.network.narkive.com/Px6EH3yl/bird-1-3-6-show-bgp-summary…

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Adding more then one bgp community at once
by Борис Коваленко 05 May '23

05 May '23

Hello! Is this possible to add many communites at once? bgp_community.add([(1,1), (1,2)]) is wrong "Setting clist attribute to non-clist value" Regards, Boris -- С уважением, Борис Коваленко

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Expiration for ROA tables until when the VRP is valid?
by Robert Scheck 07 Mar '23

07 Mar '23

Hello all, rpki-client recently implemented the "expires" instruction for roa-sets that OpenBGPD provides [1][2]. As of writing, BIRD does not seem to have something similar...any chance for it? From my understanding this only applies to included ROA files with VRP, not to RTR. [1] https://man.openbsd.org/bgpd.conf#roa-set [2] https://github.com/rpki-client/rpki-client-openbsd/commit/7bf63da6ec80f37bd… Kind regards Robert Scheck

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[PATCH] feature to keep protocol's state while configuring
by Alexander Zubkov 29 Jan '23

29 Jan '23

Hello. I have created a patch (attached) with new protocol option: disabled keep on|off. To keep the protocol's state while loading new config. It is useful when protocols disabled manually in the runtime, but we want to keep that state when loading new config. Patch is attached. I have made it against the current int-new branch.

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how can i dynamically change the gateway?
by Michele Salerno 16 Oct '22

16 Oct '22

Hi, I have this script that configures routes for me between different routers and servers. I have a few routers that have down in the wan and connect with the mesh network. How can I dynamically change the gateway? Example: if the wan drops, use the mesh as the gateway. # Configure logging log syslog all; log "/var/log/bird.log" all; log stderr all; router id from "br-lan"; # Sync bird routing table with kernel protocol kernel kernel4 { description "Kernel protocol for IPv4"; metric 50; ipv4 { table master4; export filter { if proto = "lan" then reject; accept; }; import all; }; }; protocol kernel kernel6 { description "Kernel protocol for IPv6"; metric 300; ipv6 { table master6; export filter { if proto = "lan" then reject; accept; }; import all; }; }; protocol device { description "Device protocol"; }; protocol direct lan { description "LAN protocol"; ipv4; ipv6; interface "br-lan"; check link; } protocol babel ninux { description "Babel protocol for NINUX network"; ipv4 { export where (source = RTS_DEVICE) || (source = RTS_BABEL); }; ipv6 { export where (source = RTS_DEVICE) || (source = RTS_BABEL); }; interface "vpnbas" { check link; }; ## Used to connect with other neighbours on the same layer 2 network. ## Decomment the config to use it, not this comments of course! ## Use the correct name interface, not the logical openwrt/(l)uci one. ## You can define more interfaces maches using * in regex (like "ifnet*") ## or "ifnet1", "ifnet2", "ifnetN", "otherifnetnames" form. ## You can also define more interfaces with other parameters, please refer to: ##https://bird.network.cz/?get_doc&v=20&f=bird-6.html#ss6.1 ## After, reload the bird daemon with: /etc/init.d/bird reload ## or if you perefer, reastart with: /etc/init.d/bird restart interface "mesh" { type wireless; # or wired check link; }; }

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Link local vs global v6 next hop for BGP rotuer
by Mazur, Dariusz 10 Oct '22

10 Oct '22

Hello, In my setup I have iBGP session with peer , and I learn v6 route. It is iBGP so we have 2 next hops global and link-local. By default bird uses link-local when route is exported to kernel. Is there any command to change this behavior and use global v6 address as BGP next hop when we export routes to kernel ? Table master6: fc00:2001:100:12::/64 unicast [2001:4878:c225::1:3:2__r02.ien.labkrk01.sdn 12:57:29.076] * (100) [i] via 2001:4878:c225::1:3:2 on eth-1\1\4 Type: BGP univ BGP.origin: IGP BGP.as_path: BGP.next_hop: 2001:4878:c225::1:3:2 fe80::1:3:2 BGP.local_pref: 400 BGP.community: (20940,550) Thanks, Dariusz

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Wrong BGP NH metric
by Mihai 07 Oct '22

07 Oct '22

Hello, First I would like to thank you for this amazing software! I am running Bird 2.0.7 as RR for L3VPNs and on one RR the OSPF metric for the BGP NH is different than what's seen in BGP as shown below. BGP PREF/METRIC = (100/61580) , OSPF_METRIC = 61480. bird> sh route 10:10 94.207.96.0/19 all primary Table vpntab4: 10:10 94.207.96.0/19 unicast [ROUTER1 2022-09-28 00:10:09 from 10.100.186.1] * (100/61580) [AS15802i] Type: BGP univ BGP.origin: IGP BGP.as_path: 15802 BGP.next_hop: 10.100.184.8 bird> sh route 10.100.184.8/32 Table master4: 10.100.184.8/32 unicast [OSPF 2022-09-29 12:33:35] IA (150/61480) [10.100.186.5] After restarting the BIRD OSPF adjancency the BGP metric changed to 61480. Any help in understanding the issue would be much appreciated. Thank you!

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bgp keepalive and expired issues on bird 1.6.8
by 안상혁 04 Oct '22

04 Oct '22

Hello, we have encountered some issues using bird 1.6.8 there are two issues : 1) sometimes bird looks like doesn't handle neighbor's bgp keepalive messages. when we get bgp hold timer exprired issue, on tcpdump there are keepalive packets that neighbor physical router sent and the server replied. but there is no "Got KEEPALIVE" messages on bird.log and bgp session closed after "Error: Hold timer expired" message. 2) bgp session exprired less than bgp hold timer value. we set BGP hold timer to 9 seconds, but bgp expired in 7 seconds In logs got it: 2022-08-28 10:25:55 <TRACE> as1: Got KEEPALIVE <- 10:25:56 ( got keepalived from as1 neighbor on tcpdump but not on bird.log ) <- 10:25:59 ( got keepalived from as1 neighbor on tcpdump but not on bird.log ) 2022-08-28 10:26:02 <RMT> as1: Error: Hold timer expired 2022-08-28 10:26:02 <TRACE> as1: BGP session closed bgp neighbor is physical router. have you got reported this cases? or we should upgrade to bird 2? Thank you and best regards, ted

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