May 2014 - Bird-users - Mailing Lists

New in BIRD
by Ilias Pallikarakis 23 Aug '16

23 Aug '16

Hi, I recently started trying to learn BIRD. I should also mention I have no previous experience with any other Routing daemon either. I want to configure a bgp monitor for both ipv4 and ipv6. I am running BIRD in a Ubuntu 13.10 VM. I managed to install both bird and bird6 but I have some problems with the configurations. In ipv4 : I created a very simple configuration which I attach. The conf is compiled but in birdc the bgp session is considered idle. I tried to do a tcpdump and found that the router sends a TCP SYN on the VM's bgp port but the VM responds with a RST and never tries to set a BGP session itself. In ipv6 : No matter the configuration (my configuration or the sample coming with bird6 or examples found on the web) the configuration is not compiled giving the following error : BIRD ipv6 doesn't run (bird: /usr/local/etc/bird6.conf, line 1: Router ID must be configured manually on IPv6 routers) Could anyone give me some pointers on what I am doing wrong ? Thank you for your help, Ilias Pallikarakis

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IS-IS
by kveri new 01 Jun '15

01 Jun '15

Hello, I would like to implement IS-IS as a part of my master thesis. Are there any apparent problems which would prevent successful implementation, political and/or technical? Also I would like to hear opinions of the authors. Implementation timeframe is 2013 (if we live past 21th). Regards, Martin Čechvala Faculty of Informatics and Information Technologies Slovak Technical University

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RIP not doing "triggered update" following route deletion
by Tore Anderson 15 Oct '14

15 Oct '14

I've noticed that BIRD doesn't withdraw (i.e., advertising them with metric 16) RIP routes when they disappear from the routing table. This means that the neighbour router ends up waiting for the route to time out before ceasing to send traffic to the BIRD router, rather than doing so immediately. I'm running v1.4.0 with a bird.conf containing: log syslog { info, remote, warning, error, auth, fatal }; router id 192.0.2.1; protocol device {} protocol direct {} protocol rip { interface "*" { mode nolisten; ttl security on; }; import none; export all; } To reproduce the issue, look at "tcpdump -v port 520" while doing: 1) ip address add 192.0.2.2/32 dev lo -> a triggered update appears (advertising 192.0.2.2/32) 2) ip address delete 192.0.2.2/32 dev lo -> a triggered update doesn't appear (it should have) For what it's worth, step #2 does increase the RIP protocol's "Export withdraws" counter. This issue also applies to RIPng/bird6. AFAICT, not sending these triggered updates immediately is a standards violation. Quoting RFC 1812 F.2: «A router MUST send a triggered update when routes are deleted or their metrics are increased.» Also see RFC 2453 section 3.10.1. Tore

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BFD implementation in 1.4.0
by Aleksey Berezin 02 Sep '14

02 Sep '14

Hi there! Firstly, sorry for my French ;) Recently I tried to test BFD implementation in 1.4.0 BIRD release. Case is "OSPF ECMP with less-second failover". On one side - Extreme Networks switches, other side - several boxes with Debian and BIRD, of course. So, I find out several annoying things. First thing: BIRD BFD implementation uses non-RFC5881 source UDP port for outgoing packets. Here some tcpdump: =-=-=--=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-= 20:34:21.355747 <BIRD_BOX_MAC> > <EXTREME_SW_MAC>, ethertype 802.1Q (0x8100), length 70: vlan <vlan>, p 0, ethertype IPv4, (tos 0xc0, ttl 255, id 20806, offset 0, flags [none], proto UDP (17), length 52) <BIRD_BOX_IP>.39156 > <EXTREME_SW_IP>.3784: BFDv1, length: 24 Control, State Init, Flags: [none], Diagnostic: No Diagnostic (0x00) Detection Timer Multiplier: 5 (5000 ms Detection time), BFD Length: 24 My Discriminator: 0x8a82eb8a, Your Discriminator: 0x00000002 Desired min Tx Interval: 1000 ms Required min Rx Interval: 10 ms Required min Echo Interval: 0 ms =-=-=--=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-= I saw many messages in switch logs: > <Warn:BFD.RxPktInv> Received BFD an invalid packet on VLAN <vlan> Error:Invalid UDP src port Number BFD session between BIRD and Extreme Networks switch can't be established. So, src port for outgoing BFD-packet from BIRD is 39156, when RFC5881 contains: =-=-=--=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-= 4. Encapsulation BFD Control packets MUST be transmitted in UDP packets with destination port 3784, within an IPv4 or IPv6 packet. The source port MUST be in the range 49152 through 65535. =-=-=--=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-= Ok, fixing (only for test purposes): =-=-=--=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-= root@debian-1:~# sysctl net.ipv4.ip_local_port_range net.ipv4.ip_local_port_range = 32768 61000 root@debian-1:~# sysctl -w net.ipv4.ip_local_port_range="49152 65535" net.ipv4.ip_local_port_range = 49152 65535 root@debian-1:~# sysctl net.ipv4.ip_local_port_range net.ipv4.ip_local_port_range = 49152 65535 =-=-=--=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-= After this BFD session was estabilished. Of course, net.ipv4.ip_local_port_range tuning seems to be not usable in production environment, and need to be fixed in BIRD, I think. Just because some network hardware vendors interprets RFC's exactly as written ;) But now - second thing: 'protocol bfd' block in bird.conf useless. Here part of config: =-=-=--=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-= protocol bfd FOR_OSPF { interface <BIRD_BOX_IP>/32 { interval 50 ms; min rx interval 50 ms; # presence of this string by the docs does not matter min tx interval 50 ms; # presence of this string by the docs does not matter multiplier 3; }; neighbor <EXTREME_SW_IP> dev "<BIRD_BOX_IP>" local <BIRD_BOX_IP>; # presence of this string by the docs does not matter }; protocol ospf OSPF1 { ... area 0.0.0.0 { interface <BIRD_BOX_IP>/32 { ... bfd; }; }; ... }; =-=-=--=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-= And what I see with tcpdump: =-=-=--=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-= 13:09:05.433336 <BIRD_BOX_MAC> > <EXTREME_SW_MAC>, ethertype 802.1Q (0x8100), length 70: vlan <vlan>, p 0, ethertype IPv4, (tos 0xc0, ttl 255, id 6662, offset 0, flags [none], proto UDP (17), length 52) <BIRD_BOX_IP>.62698 > <EXTREME_SW_IP>.3784: BFDv1, length: 24 Control, State Up, Flags: [none], Diagnostic: No Diagnostic (0x00) Detection Timer Multiplier: 5 (500 ms Detection time), BFD Length: 24 My Discriminator: 0x35e75227, Your Discriminator: 0x00000007 Desired min Tx Interval: 100 ms Required min Rx Interval: 10 ms Required min Echo Interval: 0 ms =-=-=--=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-= There is no any configured intervals and multiplier. Just default values. I think this is not correct. Maybe I misconfigure BIRD? Please advise. Thanks for attention.

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[PATCH] Add symbol support for various string options
by Frederik Kriewitz 05 Jun '14

05 Jun '14

Hello, during some bird config optimizations (redundancy reductions) we noticed that various string options doesn't accept symbols as value. Attached you find a patch which fixes that. Best Regards, Frederik Kriewitz

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Stale Routes -- Long Uptime?
by Stephen Holmes 20 May '14

20 May '14

Bird Users, BIRD version 1.2.5 Uptime > 3 years, nice work guys! Two identical servers running BIRD with identical config. I ran into some routes sticking around in some of my route server tables from a neighbor that was down. I did some testing and I had some success reloading the pipe protocols, but not 100%. Even with that neighbor and all it's pipes completely removed from the config the routes remained, originating from the de-configured bgp peer. During my testing I decided to do a mass reload of all the pipes to/from that down neighbor and that actually crashed the bird process, goodbye uptime. The crash did clear up the stale routes of course. I decided to just go ahead and restart my secondary route server as well to clean up the routes there. I am writing to see if others have had this experience with stale routes. My version is really old, could this be a bug that has not surfaced? Could the long uptime have lead to weirdness? Lastly, is there a configuration issue that could lead to this? I am not seeking a definitive response, or a dive into my configs, as there seem to be a lot of factors that might never point to a cause, just looking to see if others have had a similar experience. I just did a preliminary test and the configs work fine on 1.4.3 so the plan for now is to simply upgrade in the hopes this doesn't resurface. -Stephen

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Neighbors dissapears
by Александр 14 May '14

14 May '14

Hello! I have the following problem: several servers connected via openvpn tap tunnels if I set "type broadcast;" on tap interfaces - everything is ok but I'd like to filter neighbors and set type pointomultipoint; strict nonbroadcast yes; neighbors { x.x.x.x; } at initial moment - everything is ok, "show ospf neighbors" shows all defined neighbors in state "full/ptp", but after some time part of neighbors dissapears!!! tunnel is ok, I can ping neighbors ip, tcpdump show ospf hello packages. only possibile solution to return neighbors back is to call "restart all" or simply restart bird.. any ideas how to make neighbors to be all the time?

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Attack of DDOS
by Virgilio Pavel 05 May '14

05 May '14

Hi, I have a question. How can I do my bird.conf reject a DDOS Attack? Can I do this in my bird.conf? protocol static { (...) route x.w.y.z/32 reject; (...) } Best regards, []'s Virgilio Pavel

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[PATCH] Fix protocol memory use free under certrain configure/undo cases
by Sergey Popovich 05 May '14

05 May '14

It is possible to cause BIRD to use after free memory block, allocated to the protocol in the following conditions: bird.conf: --------- router id 1.1.1.1; protocol static static1 { route 0.0.0.0/0 blackhole; } protocol static static2 { route 0.0.0.0/0 blackhole; } Start bird. On the console do: BIRD 1.3.11 ready. name proto table state since info static1 Static master up 18:17:30 static2 Static master up 18:17:30 Edit bird.conf and comment out protocol static2 (or static1, this does not important). Save configuration file candidate. Then on console do: BIRD 1.3.11 ready. name proto table state since info static1 Static master up 18:19:02 See no protocol static2, it is freed in proto_rethink_goal(), but still in old (BIRD's startup config) config structure, thus not initialized as new on undo operation at protos_commit(). And after this we have use after free protocol structure, which is already removed after first configure, where protocol commented out in config. In certrain environments (especially with glibc compiled to detect double free corruptions) this leads to BIRD crash. Fix by initializing pointer to the protocol in configuration file when protocol is candidate for removal (all cases where cf_new is set to NULL). Signed-off-by: Sergey Popovich <popovich_sergei(a)mail.ru> --- nest/proto.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/nest/proto.c b/nest/proto.c index edb490f..c21be85 100644 --- a/nest/proto.c +++ b/nest/proto.c @@ -599,7 +599,10 @@ proto_rethink_goal(struct proto *p) rem_node(&p->glob_node); mb_free(p); if (!nc) - return; + { + p->cf->global->proto = NULL; + return; + } p = proto_init(nc); } -- 1.7.10.4

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segfault with exabgp and bird 1.4.2
by Charlie Allom 03 May '14

03 May '14

Hi, I have been running a stable mesh with a BIRD peer in a mesh for a few weeks now. Trying to connect with ExaBGP makes BIRD segfault. How can I debug this further? Here is the TCP stream: https://spodder.com/~yeled/bird.pcap It seems innocuous to me. C. ~% ulimit -c 100000 ~% file ./bird ./bird: ELF 64-bit LSB executable, x86-64, version 1 (SYSV), for GNU/Linux 2.6.8, dynamically linked (uses shared libs), not stripped ~% sudo ./bird bird: Hello or poll interval less that 5 makes cryptographic authenication prone to replay attacks ~% sudo ./birdc BIRD 1.4.2 ready. Connection closed by server. ~% sudo gdb bird core GNU gdb 6.8-debian Copyright (C) 2008 Free Software Foundation, Inc. License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html> This is free software: you are free to change and redistribute it. There is NO WARRANTY, to the extent permitted by law. Type "show copying" and "show warranty" for details. This GDB was configured as "x86_64-linux-gnu"... warning: Can't read pathname for load map: Input/output error. Reading symbols from /lib/librt.so.1...done. Loaded symbols for /lib/librt.so.1 Reading symbols from /lib/libpthread.so.0...done. Loaded symbols for /lib/libpthread.so.0 Reading symbols from /lib/libc.so.6...done. Loaded symbols for /lib/libc.so.6 Reading symbols from /lib/ld-linux-x86-64.so.2...done. Loaded symbols for /lib64/ld-linux-x86-64.so.2 Core was generated by `./bird'. Program terminated with signal 11, Segmentation fault. [New process 11480] #0 bgp_rx (sk=0x6aa930, size=<value optimized out>) at ../../../proto/bgp/packets.c:1030 1030 ../../../proto/bgp/packets.c: No such file or directory. in ../../../proto/bgp/packets.c (gdb) bt #0 bgp_rx (sk=0x6aa930, size=<value optimized out>) at ../../../proto/bgp/packets.c:1030 #1 0x00000000004396f3 in sk_read (s=0x6aa930) at io.c:1602 #2 0x000000000043ab03 in io_loop () at io.c:1843 #3 0x000000000043d7a1 in main (argc=<value optimized out>, argv=<value optimized out>) at main.c:820 (gdb)

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