September 2016 - Bird-users

Version 1.6.2
by Ondrej Filip 31 Aug '17

31 Aug '17

Dear users, a new version of the 1.6.x branch is out: Version 1.6.2 (2016-09-29) o Fixes serious bug introduced in the previous version Upgrade from 1.6.1 is highly recommended. Enjoy it! Ondrej

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BGP Monitoring Protocol (BMP) support in Bird?
by Baptiste Jonglez 11 Jul '17

11 Jul '17

Hi, I am wondering if somebody is working on BGP Monitoring Protocol (BMP) support in Bird? Note that I'm just asking, I'm not requesting our beloved Bird developers to add this feature with a deadline set to yesterday :) I might try to implement it if nobody else already did. Basically, this is just a way to export BGP data over a TCP connection: http://tools.ietf.org/html/rfc7854 This looks like a useful alternative to dumping to mrtdump files, there are already several free software clients: https://code.google.com/archive/p/bmpreceiver/ http://www.openbmp.org/#!index.md Baptiste

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CLI debugging
by micah anderson 12 Oct '16

12 Oct '16

Hi, I wanted to debug the states of a neighbor, but I cannot seem to figure out how to change debugging on the command-line in a way that *seems* according to the argument options: debug (<protocol> | <pattern> | all) (all | off | { states | routes | filters | interfaces | events | packets }) Control protocol debugging via BIRD logs BIRD 1.6.0 ready. bird> debug all states syntax error bird> debug all events syntax error bird> debug cogent states syntax error bird> debug cogent events syntax error bird> debug cogent all bird> The 'all' works, but the others do not. Do I misunderstand the argument option specification? Thanks, micah

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protocol kernel segfault
by Julien Sansonnens 29 Sep '16

29 Sep '16

Hi list, I'm using bird 1.6.1 on debian Jessie. For some reason (COULD be related to updating to 1.6.1, but not sure), bird6 is not working anymore. It used to work some weeks ago. The problem is related to "protocol kernel". When I set it like this: protocol kernel { import none; export all; } it crashed bird6. Everytime I get this segfault: Sep 29 12:24:11 mymachine kernel: [ 8588.114910] bird6[2974]: segfault at 0 ip (null) sp 00007ffd04645608 error 14 in libnss_files-2.19.so[ 7f91281db000+b000] When I remove this protocol, everything is working fine. Please can you help ? Thanks Julien

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OSPF "hack translation" sought
by Clemens Schrimpe 29 Sep '16

29 Sep '16

Gentlepeople - I was wondering what the "translation" of the usual hack on Quagga/JunOS/etc. for OSPF into a proper BIRD config was to allow OSPF to propagate routes to directly connected networks, which are not really part of an OSPF area. In those other systems I would make those interfaces just "passive" members, but BIRD doesn't know "passive interfaces". Making them stubs has obvious other side effects, which is why I just want the "passive" hack to work under BIRD. So what's the equivalent to do this in BIRD? Thanks, Clemens Schrimpe

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filter all prefixes except a few with 'case' control
by Войнович Андрей Александрович 29 Sep '16

29 Sep '16

Hi all! I try to implement simple filter which rejects all prefixes except a few with 'case' control this way: filter permit_white { case net { 1.1.1.1/32: accept; 2.2.2.2/32: accept; else: reject; } } But syntax check fails on line '1.1.1.1/32: accept;'. I read everything on Internet what was found, but cannot understand what is wrong. ------------------------------------------ Служба поддержки серверов Группа сетевого администрирования ДПП.УТП.СПС ЗАО ПФ <СКБ-Контур>, Тел. +7 (343) 344-11-50 доб. 75352 e-mail: dc-noc(a)skbkontur.ru<mailto:dc-noc@skbkontur.ru> https://www.kontur.ru<https://www.kontur.ru/>

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BIRD patches for IP-in-IP
by Neil Jerram 29 Sep '16

29 Sep '16

Hi BIRD users! Attached are 3 patches that my team has been using for routing through IP-in-IP tunnels, rebased on 1.6.1. I'd like to explain why we find them useful, and start a conversation about whether they or something like them could be upstreamed (or perhaps if there's some better way of achieving our aims). Calico [1] uses BIRD for BGP routing between the hosts in various cloud orchestration systems (Kubernetes, OpenStack etc.), to distribute routes to the pods/VMs/containers in those systems, each of which has its own IP. If all the hosts are directly connected to each other, this is straightforward, but sometimes they are not. For example GCE instances are not directly connected to each other: there is at least one router between them, that knows about routing GCE addresses, and to/from the Internet, and we cannot peer with it or otherwise tell it how to route pod/VM/container IPs. So if we use GCE to create e.g. OpenStack compute hosts, with Calico networking, we need to do something extra to allow VM-addressed data to pass between the compute hosts. One of our solutions is to use IP-in-IP; it works as shown by this diagram: 10.65.0.3 via 10.240.0.5 dev tunl0 onlink default via 10.240.0.1 | +-|----------+ +------------+ | o | | | | Host A | +--------+ | Host B | | |---------| Router |----------| | | 10.240.0.4 | +--------+ | 10.240.0.5 | | |---. | | +------------+ | +------------+ ^ ^ +---v---+ | src 10.65.0.2 | | | tunl0 | | dst 10.65.0.3 | | +-------+ | | \ | v +-----------+ '----' +-----------+ | Pod A | src 10.240.0.4 | Pod B | | 10.65.0.2 | dst 10.240.0.5 | 10.65.0.3 | +-----------+ ------ +-----------+ src 10.65.0.2 dst 10.65.0.3 The diagram shows Pod A sending a packet to Pod B, using IP addresses that are unknown to the 'Router' between the two hosts. Host A has an IP-in-IP device, tunl0, and a route that says to use that device for data to Pod B's address (10.65.0.3). When the packet has passed through that device, it has a new outer IP header, with src 10.240.0.4 and dst 10.240.0.5, and is routed again according to the routing table - so now it can successfully reach Host B. So how is BIRD involved? We statically program the local Pod route on each host: On Host A: 10.65.0.2 dev <interface to Pod A> On Host B: 10.65.0.3 dev <interface to Pod B> then run a BIRD BGP session between Host A and Host B to propagate those routes to the other host - which would normally give us: On Host A: 10.65.0.3 via 10.240.0.5 On Host B: 10.65.0.2 via 10.240.0.4 But we don't want those normal routes, because then the data would get lost at 'Router'. So we enhance and configure BIRD as follows. - In the export filter for protocol kernel, for the relevant routes, we set an attribute 'krt_tunnel = tunl0'. - We modify BIRD, as in the attached patches, to understand that that means that those routes should have 'dev tunl0'. Then instead, we get: On Host A: 10.65.0.3 via 10.240.0.5 dev tunl0 onlink On Host B: 10.65.0.2 via 10.240.0.4 dev tunl0 onlink which allows successful routing of data between the Pods. Thanks for reading this far! I now have three questions: 1. Does the routing approach above make sense? (Or is there some better or simpler or already supported way that we could achieve the same thing?) 2. If (1), would the BIRD team accept patches broadly on the lines of those that are attached? 3. If (2), please let me know if the attached patches are already acceptable, or otherwise what further work is needed for them. Many thanks, Neil

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Problems after upgrade to 1.6.1 from 1.6.0
by Ralf Hildebrandt 28 Sep '16

28 Sep '16

I upgraded BIRD from a working 1.6.0-3+trusty+1 to 1.6.1-1+trusty+1 today (from the Ubuntu PPA https://launchpad.net/~cz.nic-labs/+archive/ubuntu/bird ) Then bird started to segfault: Sep 28 11:46:24 dns-ccm kernel: [4320833.655332] bird[10188]: segfault at 0 ip (null) sp 00007fff3f9624a8 error 14 in bird[5654a2004000+70000] Sep 28 11:46:24 dns-ccm kernel: [4320833.685949] bird[16543]: segfault at 0 ip (null) sp 00007ffe7e13f2c8 error 14 in bird[55d29a334000+70000] I rebuilt the package from the PPA sources without debugging and ran bird in gdb: # gdb ./build-ipv4/bird (gdb) set args -f -u bird -g bird (gdb) run Starting program: /usr/src/bird-1.6.1/build-ipv4/bird -f -u bird -g bird [Thread debugging using libthread_db enabled] Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1". 2016-09-28 15:00:31 <INFO> Chosen router ID 141.42.1.11 according to interface bond0 2016-09-28 15:00:31 <INFO> Started Program received signal SIGSEGV, Segmentation fault. 0x0000000000000000 in ?? () (gdb) bt #0 0x0000000000000000 in ?? () #1 0x00005555555b8812 in sk_err (s=0x5555558077d0, revents=9) at io.c:1867 #2 0x00005555555b93f1 in io_loop () at io.c:2237 #3 0x00005555555bec05 in main (argc=6, argv=0x7fffffffe5e8) at main.c:883 (gdb) bt full #0 0x0000000000000000 in ?? () No symbol table info available. #1 0x00005555555b8812 in sk_err (s=0x5555558077d0, revents=9) at io.c:1867 se = 0 sse = 4 #2 0x00005555555b93f1 in io_loop () at io.c:2237 s = 0x5555558077d0 count = 1 poll_tout = 1000 tout = 4332491 nfds = 3 events= 0 pout = 1 s = 0x55555581ac20 n = 0x5555557f3d88 <sock_list+8> fdmax = 256 pfd = 0x5555558120c0 #3 0x00005555555bec05 in main (argc=6, argv=0x7fffffffe5e8) at main.c:883 use_uid = 115 use_gid = 128 conf = 0x5555557f8b80 (gdb) My config: ========== ---- SNIP ---- log stderr all; router id from "bond0"; # Funktion in der die verwendeten ANYCAST-IPs eingetragen werden muessen function is_anycastIP () { return net ~ [ 141.42.1.1/32, 141.42.1.2/32 ]; } # Direkte Interface-Routen (z.B. die an "lo" gebundene ANYCAST-IP) lernen protocol direct { interface "lo"; } # Exportieren der OSPF-Routen an die Kernel-Routingtable, keine Imports! protocol kernel { scan time 20; import none; export all; preference 100; } # Lokale Devices/Interfaces einbeziehen. # u.a. fuer die automatische Erkennung der RouterID notwendig protocol device { scan time 10; } protocol ospf ANYCAST { rfc1583compat yes; tick 2; preference 50; ecmp yes; import filter { # Default-Route und die von den anderen kommenden ANYCAST-IPs nicht aus OSPF importieren if ((net = 0.0.0.0/0) || is_anycastIP()) then { reject; } accept; }; export filter { # Nur die ANYCAST-IPs ins OSPF propagieren if ((source = RTS_DEVICE) && is_anycastIP()) then { # E1-Route mit Kosten=5000 erzeugen ospf_metric1 = 5000; accept; } reject; }; area 0 { interface "bond0" { type broadcast; hello 10; retransmit 5; wait 40; dead 40; check link; priority 0; cost 5000; authentication cryptographic; password "SECRET"; }; }; } ---- SNIP ---- -- Ralf Hildebrandt Charite Universitätsmedizin Berlin ralf.hildebrandt(a)charite.de Campus Benjamin Franklin http://www.charite.de Hindenburgdamm 30, 12203 Berlin Geschäftsbereich IT, Abt. Netzwerk fon: +49-30-450.570.155

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Version 1.6.1
by Ondrej Filip 27 Sep '16

27 Sep '16

Dear users, a new version of the 1.6.x branch is out: Version 1.6.1 (2016-09-22) o Support for IPv6 ECMP o Better handling of IPv6 tentative addresses o Several updates and fixes in Babel protocol o Filter: New !~ operator o Filter: ASN ranges in bgpmask o KRT: New kernel protocol option 'metric' o KRT: New route attribute 'krt_scope' o Improved BIRD help messages o Fixes memory leak in BGP multipath o Fixes handling of empty path segments in BGP AS_PATH o Several bug fixes Enjoy it! Ondrej

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Improving Anycast routing with Bird
by Kyle Drake 22 Sep '16

22 Sep '16

Hello! I'm new to using Bird and BGP, but I'm learning. I've recently acquired an IPv4/24, and I've been working on building an Anycast network for CDN use. Right now I have a 15 datacenter network from a VPS provider (which uses Bird as it's recommended daemon: https://www.vultr.com/docs/configuring-bgp-on-vultr) Using their configuration example, I was able to get an anycast network up without any modification. That part is working great! The problem I have now is figuring out how to improve the routing. For example, Comcast users in Portland, OR are being sent to Los Angeles, even though the closest server is in Seattle (confirmed with traceroute). The underlying BGP problem seems to be that Comcast sees multiple routes as 2 AS routes (7922 20473), so it doesn't understand that the Seattle instance is preferred here. There are many more examples like this I've found, and I'm trying to figure out what an approach might be to try to improve this. Is there a way to improve routing using bird export filters or some other mechanism I'm not familiar with? Can I use Bird to steer certain traffic to closer servers, or to only announce routes to regional BGP servers? Or is this largely out of my control and I need to accept these non-ideal routes? I've also been told I might be able to use BGP communities for this, but I've never worked with communities directly, so I don't understand how they would help me here. This is the list of communities I have available to me: https://www.vultr.com/docs/as20473-bgp-customer-guide Thank you in advance for any ideas or code examples here. There is zero documentation on tuning Anycast out there (even the old school BGP books I've skimmed through barely mention anycast). Here is my current bird.conf: log syslog all; router id **MY_IP**; protocol bgp vultr { local as 395409; source address **MY_IP**; import none; export all; graceful restart on; multihop 2; neighbor **BGP_IP** as 64515; password "**OBSCURED**"; } protocol static { route 198.51.233.0/24 via **MY_IP**; } protocol device { scan time 5; } protocol direct { interface "neocities*"; import all; } -Kyle

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