July 2023 - Bird-users - Mailing Lists

Recursive nexthop via kernel route in proto static not working
by Daniel Gröber 15 Aug '23

15 Aug '23

Hi, I'm trying to configure a static route that uses the system's default router. The default router is out of my control and is announced via IPv6 RA. Since the MAC might not be stable I'd prefer not to hardcode the router's link-local address. So I tried: protocol static static_export_kernel2 { ipv6; igp table master6; route 2001:db8::/48 recursive ::; } The thinking being that :: ought to be resolvable through the default route imported from proto kernel: birdc show route for :: all Table master6: ::/0 unicast [kernel1 2023-03-22] * (10) via fe80::fc00:3ff:fec7:cd05 on enp1s0 Type: inherit univ Kernel.source: 9 Kernel.metric: 1024 Kernel.hoplimit: 64 However the static route ends up being "unreachable": 2a0d:f302:114::/48 unreachable [static_export_kernel2 13:59:32.819] * (200) Type: static univ Any ideas why this isn't working? Thanks, --Daniel PS: The reason I have to create this static route when it's already covered by the default route has to do with an esoteric policy routing setup and multiple routing daemons ask for details at your own peril :)

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OSPF Router communications
by John He 28 Jul '23

28 Jul '23

For OSPF, is it possible to have router communications in a different subnet than for the next-hop IP addresses? For example, running OSPF on an interface eth0 with IP address 10.0.0.1/24, and want to send an LS Update message with LSA for a network, with the Forwarding Address set to an IP address not on this subnet.

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changing bgp_med attributes cause route been filited
by Brandon Zhi 27 Jul '23

27 Jul '23

Hi all, I was doing research about selecting the best route on multiple nodes based on bgp_med attributes. function ibgp_import(int bgp_med_ping; int extra_bgp_med){ add_type("ibgp"); if is_bogon_asn() then { print "is bogon asn", net, " for ASN ", bgp_path.last; return false; } if is_bogon_prefix() then { print "is bogon prefix", net, " for ASN ", bgp_path.last; return false; } if (LOCAL_ASN, 47, NODE_ID) ~ bgp_large_community then { reject; } if bgp_large_community ~ [(LOCAL_ASN, 2, 100)] then preference = 115; additional_import_action(); bgp_med = bgp_med + bgp_med_ping + bgp_med_ping; return true; } My idea is to add bgp_med value between each node based on ping, and then bird will select the route which has the lowest bgp_med value (which is the total ping delay) But some routes will be filled, which i don't want it. I found that the code " bgp_med = bgp_med + bgp_med_ping + bgp_med_ping;" will cause some routes to be filtered. Can someone tell me why? I only want to modify bgp_med and don't want my routes to be filtered. Best, *Brandon Zhi* HUIZE LTD www.huize.asia <https://huize.asia/>| www.ixp.su | Twitter This e-mail and any attachments or any reproduction of this e-mail in whatever manner are confidential and for the use of the addressee(s) only. HUIZE LTD can’t take any liability and guarantee of the text of the email message and virus.

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two AS announce config migration 1.6.6 -> 2.0.12
by nixx 27 Jul '23

27 Jul '23

Hello. I need to announce one autonomous system from under another so that the path "world -> AS65007 -> AS65065" must be visible from the outside world. I successfully do it on version 1.6.6 (config-file and 'show route' from live system with changed ip-addresses in attach). Exactly the same method does not work on version 2.0.12 - for unknown reason I get ALL imported from second AS static routes in the unreachable state (bird-2.0.12-config with 'show route' at the end of file). Has something changed in the work process of the bird, or am I doing something wrong? bird 1.6.6 on debian 10 / kernel 4.19.181 bird 2.0.12 on debian 11 / kernel 5.10.179 Peering interfaces on both systems are created as follows: auto enp129s0.699 iface enp129s0.699 inet static address 10.99.11.1/30 vlan-raw-device enp129s0 auto enp129s0.699:0 iface enp129s0.699:0 inet static address 10.99.11.2/30 vlan-raw-device enp129s0

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Remove all except one community
by Marek Küthe 19 Jul '23

19 Jul '23

Hello, I recently discovered a new filter for myself on https://bgpfilterguide.nlnog.net/guides/many_communities/#bird. In my eyes it also makes sense to keep the routing table as small as possible. But now I don't want to delete all communities, but keep a single one. How can I implement something like that? ``` function strip_too_many_communities() { if ( ( bgp_community.len + bgp_ext_community.len + bgp_large_community.len ) >= 100 ) then { bgp_community.empty.except((64511, *)); bgp_ext_community.empty; bgp_large_community.empty; } } ``` The background is that these serve in the [dn42](https://dn42.dev/howto/Bird-communities) as information, how good the connection to the destination is. Therefore I would like to keep these. Does anyone have any ideas on how to do something like this? Greetings Marek Küthe -- Marek Küthe m.k(a)mk16.de er/ihm he/him

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bird logo and name of the bird
by Marek Küthe 19 Jul '23

19 Jul '23

Hello, I hope it's okay that I ask about this on the Mailling list. I'm currently creating a mod for UnCiv in which I'm incorporating various computer themes such as Yumi from Ubuntu Touch or Xue from Xfce Desktop (see https://codeberg.org/mark22k/UnCiv-Logicians/src/branch/main/Inspiration.md) bird also has a logo - a bird and the font "bird" below it (https://bird.network.cz/ico/head.png) I wanted to ask if the bird has a specific name? Furthermore I wanted to ask if the logo is available in a better resolution? I would be very happy about an answer! Greetings Marek Küthe -- Marek Küthe m.k(a)mk16.de er/ihm he/him

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Graceful shutdown request signal
by Erin Shepherd 17 Jul '23

17 Jul '23

Hello, I run bird on a system which uses systemd as a service supervisor, and would like to implement graceful restart in a way which works well with it. In particular, what I'd like to do is: • If I restart the bird service (e.g. for an upgrade), Bird performs a graceful restart • If I manually stop bird (systemctl stop bird2), shutdown the system, or any other action which is liable to cause a longer period of downtime, perform a graceful restart (for BGP at least) Ideally systemd would have an ExecStopRestart option which could be used to distinguish between stops and restarts, but unfortunately it doesn't (I might submit a feature request for this regardless). However, it does support `KillSignal and RestartKillSignal options.` `So therefore I was wondering how the Bird developers and users would feel about introducing a signal (SIGUSR2 maybe?) which can be used to request that Bird perform a graceful restart?` `- Erin`

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systemctl doesn't specify the syntax error during service restart/reload in bird version 2
by Jimmy Lim 05 Jul '23

05 Jul '23

Hi guys, I have just upgraded the bird version to version 2. I just wonder whether there is anything we should configure for systemd to notify us of a syntax error in bird.conf while doing systemctl reload/restart bird? It is no longer informing me somehow now. # systemctl reload bird # # systemctl restart bird Job for bird.service failed because the control process exited with error code. See "systemctl status bird.service" and "journalctl -xe" for details. # systemctl status bird.service ● bird.service - BIRD Internet Routing Daemon Loaded: loaded (/lib/systemd/system/bird.service; enabled; vendor preset: enabled) Active: failed (Result: exit-code) since Wed 2023-07-05 07:15:25 UTC; 9s ago Process: 71401 ExecStartPre=/usr/lib/bird/prepare-environment (code=exited, status=0/SUCCESS) Process: 71409 ExecStartPre=/usr/sbin/bird -p (code=exited, status=1/FAILURE) Jul 05 07:15:25 n246-040-093 bird[27010]: BGP_session1: State changed to down Jul 05 07:15:25 n246-040-093 bird[27010]: BGP_session1: Channel ipv4 removed Jul 05 07:15:25 n246-040-093 bird[27010]: BGP_session2: State changed to down Jul 05 07:15:25 n246-040-093 bird[27010]: BGP_session2: Channel ipv4 removed Jul 05 07:15:25 n246-040-093 bird[27010]: BGP_session3: State changed to down Jul 05 07:15:25 n246-040-093 bird[27010]: BGP_session3: Channel ipv4 removed Jul 05 07:15:25 n246-040-093 bird[27010]: Shutdown completed Jul 05 07:15:25 n246-040-093 systemd[1]: bird.service: Control process exited, code=exited, status=1/FAILURE Jul 05 07:15:25 n246-040-093 systemd[1]: bird.service: Failed with result 'exit-code'. Jul 05 07:15:25 n246-040-093 systemd[1]: Failed to start BIRD Internet Routing Daemon. It is only when I manually enable, it triggers the error line: # /usr/sbin/bird -f -u bird -g bird bird: /etc/bird/bird.conf:4:1 syntax error, unexpected CF_SYM_UNDEFINED I wonder whether I need to configure anything for BIRD 2? Thanks, Jimmy

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Bird does not prefer older eBGP route - RFC5004 and "older prefer on"
by Mazur, Dariusz 03 Jul '23

03 Jul '23

Hello Bird users, Have you ever use RFC 5004 and “older prefer” knob. I am trying to use it but it seems not to work: 1.Router learns the same route from different ebgp peers, it prefers route from r01a and this route is exported to BGP peers 172.232.160.0/19 unicast [192.168.196.129__r01a.tor106 2023-06-14] * (100) [AS4250627481?] via 192.168.196.129 on vlan.201 unicast [192.168.196.131__r01b.tor106 2023-06-14] (100) [AS4250627481?] via 192.168.196.131 on vlan.202 unicast [192.168.196.133__r02a.tor106 2023-06-14] (100) [AS4250627482?] via 192.168.196.133 on vlan.203 2.Once we lose links to r01a and r01b route from r02a is preferred and exported to BGP peers. It is expected 172.232.160.0/19 unicast [192.168.196.133__r02a.tor106 2023-06-14] * (100) [AS4250627482?] via 192.168.196.133 on vlan.203 3.When links to r01a and r01b. are again online route, route from r01a is pricked as primary and exported to BGP. It causes route oscillation 172.232.160.0/19 unicast [192.168.196.129__r01a.tor106 09:14:19.982] * (100) [AS4250627481?] via 192.168.196.129 on vlan.201 unicast [192.168.196.131__r01b.tor106 09:14:19.896] (100) [AS4250627481?] via 192.168.196.131 on vlan.202 unicast [192.168.196.133__r02a.tor106 2023-06-14] (100) [AS4250627482?] via 192.168.196.133 on vlan.203 4.I believe it is default behavior not to prefer older path. According to documentation RFC 5004 and "prefer older on" should fix my problem, but it does not work. Bird doc says: prefer older switch Standard route selection algorithm breaks ties by comparing router IDs. This changes the behavior to prefer older routes (when both are external and from different peer). For details, see RFC 5004. Default: off. 5. According to documentation RFC 5004 and "prefer older on" should fix my problem, but it does not work. a) added "prefer older on", bgp flapped and routes were re-learnt 172.232.160.0/19 unicast [192.168.196.129__r01a.tor106 09:22:12.949] * (100) [AS4250627481?] via 192.168.196.129 on vlan.201 unicast [192.168.196.131__r01b.tor106 09:22:13.527] (100) [AS4250627481?] via 192.168.196.131 on vlan.202 unicast [192.168.196.133__r02a.tor106 09:22:12.683] (100) [AS4250627482?] via 192.168.196.133 on vlan.203 b) shut links to r01a and r01b 172.232.160.0/19 unicast [192.168.196.133__r02a.tor106 09:22:12.683] * (100) [AS4250627482?] via 192.168.196.133 on vlan.203 c) unshut links to r01a and r01b, route from r01a is again preferred, so looks like "older" knob does not work 172.232.160.0/19 unicast [192.168.196.129__r01a.tor106 09:27:55.841] * (100) [AS4250627481?] via 192.168.196.129 on vlan.201 unicast [192.168.196.131__r01b.tor106 09:27:54.448] (100) [AS4250627481?] via 192.168.196.131 on vlan.202 unicast [192.168.196.133__r02a.tor106 09:22:12.683] (100) [AS4250627482?]. ---> this route is older via 192.168.196.133 on vlan.203 Thanks, Dariusz

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