September 2015 - Bird-users

iBGP and Next-Hop cost
by Adam Priestley 10 Sep '15

10 Sep '15

Hello list, I am trying to understand where I might be going wrong in my implementation or understanding of the following setup. I have two servers in different locations, both of which are using exabgp to advertise the same /32 loopback to their nearest bird router over eBGP. The network is logically just a ring of 6 bird routers running OSPF and an iBGP full mesh. These /32 routes are then distributed via the iBGP mesh to the rest of the network. Both routes are identical in their attributes apart from the next-hop and router-id. They have the same MED and localpref. The next-hop routes are of course known from OSPF. The documentation states that "BGP depends on existing IGP routing table with AS-internal routes to determine immediate next hops for routes and to know their internal distances to boundary routers for the purpose of BGP route selection". However: When inspecting the available routes from one of my bird routers elsewhere on the network, I see one for which the next-hop OSPF cost is 20, and one where the cost is 30. Both routes still show the same MED, the same localpref, same as-path etc, but the route with the higher OSPF cost is always being installed. The only reason I can see for this route to be preferred is that the originating router has the lower router-id, but this check comes after the supposed IGP distance check in the route selection rules. So am I completely misunderstanding how this process works, or have I just done something wrong? Any advice would be greatly appreciated. Available routes for the /32: ------------------------- root@bird1:~# birdc show route all for 10.13.83.6 BIRD 1.4.5 ready. 10.13.83.6/32 via 10.13.83.246 on eth1.10 [BIRD3 2015-09-08 from 10.13.83.2] * (100/?) [AS65100i] Type: BGP unicast univ BGP.origin: IGP BGP.as_path: 65100 BGP.next_hop: 10.13.82.65 BGP.med: 100 BGP.local_pref: 100 via 10.13.83.233 on eth0.14 [BIRD6 2015-09-08 from 10.13.83.5] (100/?) [AS65100i] Type: BGP unicast univ BGP.origin: IGP BGP.as_path: 65100 BGP.next_hop: 10.13.81.73 BGP.med: 100 BGP.local_pref: 100 Installed routes to the next-hops: ------------------------- root@bird1:~# birdc show route all primary for 10.13.82.65 BIRD 1.4.5 ready. 10.13.82.64/27 via 10.13.83.246 on eth1.10 [PackOSPF 2015-08-05] * E2 (150/30/10000) [10.13.83.2] Type: OSPF-E2 unicast univ OSPF.metric1: 30 OSPF.metric2: 10000 OSPF.tag: 0x00000000 OSPF.router_id: 10.13.83.2 root@bird1:~# birdc show route all primary for 10.13.81.73 BIRD 1.4.5 ready. 10.13.81.64/27 via 10.13.83.233 on eth0.14 [PackOSPF 2015-08-24] * E2 (150/20/10000) [10.13.83.5] Type: OSPF-E2 unicast univ OSPF.metric1: 20 OSPF.metric2: 10000 OSPF.tag: 0x00000000 OSPF.router_id: 10.13.83.5 Adam Priestley Network Administrator Packnet Limitedt: +44 (0)161 660 2350 f: +44 (0)161 660 9825 e: adam(a)pack-net.co.uk w: http://www.pack-net.co.uk/ Registered Address: PACKNET LIMITED, Duplex 2, Ducie House 37 Ducie Street Manchester, M1 2JW COMPANY REG NO. 04920552

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Route server IPv6 avoid_martians
by Jonathan Stewart 10 Sep '15

10 Sep '15

Hi, This page describes an IPv4 route-server: https://gitlab.labs.nic.cz/labs/bird/wikis/Simple_route_server I like the function avoid_martians(), and use it (mine's even been expanded a bit) I'd like to implement something similar for IPv6. Has anyone else already created a function for IPv6? I'm especially wondering about how to filter out too-long prefixes--i think that's the 0.0.0.0/0{25,32} line. Any pointers, even just to how this syntax works, would be welcome. I hope i can update the wiki with the knowledge gleaned. Thanks, Jonathan MBIX.ca

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not listening on 179 but iface up
by Kai 10 Sep '15

10 Sep '15

Dear bird gurus, :) I'm currently setting up a new iBGP-(only)-member. It is configured to connect to 2 internal peers: -------------------- protocol bgp wiesbaden1 from bgp_ibgp_wi { # lotuswurzel neighbor 10.56.0.23 as wi_as; }; protocol bgp wiesbaden2 from bgp_ibgp_wi { # kaschu neighbor 10.56.0.208 as wi_as; }; -------------------- and these 2 peers are configured to connect vice-versa. They don't connect. Additionally bird on the new member doesn't listen on port 179. I first tried it to listen explicitly on two of the hosts IP addresses (is this possible, by the way?) and now removed the explicit "listen" - so that it should now listen on 0.0.0.0:179, right? It doesn't. :( I found hints that bird may postpone opening the socket, if the network interfaces are not yet up. But at least 4 interfaces _are_ up, including the two where the iBGP peers are connected directly. Any ideas? Cheers, Kai -- "Das ist Demokratie, wenn man sich aussuchen darf, wer einen verarscht." (Hagen Rether) D-55118 Meenz fast: kai_pf (aT] web(dot)de ++ PGP Key fingerprint B567 C43E 99D1 7709 7D64 3BF8 2DE8 1092 0EEF D58E ++ -----BEGIN GEEK CODE BLOCK----- VERSION: 3.12 GCS/IT/CM d- s:- a+>-----(?) C++$ UL++(++++$) P+++ L++ E-(+) W--(+) N !w---($) !O !M V? PS+ PE-() Y+ PGP(+) t R*@ tv--@ b+>++ DI++ G e+++(*) h? y? ------END GEEK CODE BLOCK------

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OSPF & unnumbered interfaces
by Basile Bluntschli 09 Sep '15

09 Sep '15

Hi All I was trying to have OSPF run with the "ip unnumbered interface /32" methodology. So far it was working when specifing the neighbor on the other end: ip addr add 192.168.2.1 peer 10.10.10.10 dev lan3 Is there a way to have it running without a "neighbor statement"? I would like to bring up the OSPF neighborship without knowing the other end Thanks Basile

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Weird Bird BGP MRT dump
by Domingues Luis Filipe 07 Sep '15

07 Sep '15

Hi, Do anyone uses the mrtdump functionnality of Bird? I am trying to get the update BGP update message from Bird using a MRT Dump file. But when I try to parse the files I have inconsistent data. I use there parsers: https://github.com/rfc1036/zebra-dump-parser https://github.com/YoshiyukiYamauchi/mrtparse The zebra parser give me impossible addresses like 16.167.165/104 while the mrtparse just crashes. Any idea where I can look further? Regards, Luis Domingues

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Does Bird 1.5 support MPLS/LDP
by Madhuri 02 Sep '15

02 Sep '15

Hi, I have compiled the BIRD 1.5 code with --enable-mpls, and it got compiled successfully. But when I declare the table for MPLS labels i am getting the syntax error in configuration. I am not finding any code related to LDP under ../../../proto/ Using Ubuntu 15.04 and kernel 3.19.0-21 Does Bird 1.5 Support MPLS? Or Am I missing something in configuration? Thanks, Madhuri

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BFD Debugging Help
by Leighton, Russell 01 Sep '15

01 Sep '15

I'm doing this: protocol bfd { debug { states, routes, filters, interfaces, events, packets }; ... } But I only get "CTL" messages in the syslog. Is there a way to get the full verbose level of logging (packets, etc)? Thx Russ Russell Leighton Senior Software Development Engineer Amazon Web Services / EC2 Networking leightr(a)amazon.com Mobile: 301.828.8458

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