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2 routers and 4 peers route export selection
by Laurent GUERBY 27 Apr '12

27 Apr '12

Hi, I have two debian BIRD routers R1 and R2 connected by an iBGP session, both R1 and R2 are connected to two eBGP peers each: P1 <==> R1 <===> R2 <===> P3 P2 <==> | | <===> P4 Some routes are imported by R1 from both P1 and P2 and I want to continue to export to P3 a mix of routes from P1 and P2 (which is what is done by the iBGP session and preferences) but now I want to export to P4 only the routes imported from P2 and no route imported from P1. How would you do that with BIRD? Thanks in advance, Laurent

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bird + arp
by Amadeus 26 Apr '12

26 Apr '12

Hi, is there any easy way right now to advertise host routes from kernel's arp table as soon as they appear? Best wishes Amadeus

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functions question
by Jaroslav Jirásek 18 Apr '12

18 Apr '12

Hello, I want to do function, which adds many communities in one function call now I use it like this: function add_community(pair peer_community) { bgp_community.add(peer_community); return true; } add_community((11111, 4444)) && add_community((11111, 5555)) && add_community((2222, 6666)) and I want to do something like this: function add_community(pair set peer_community) { bgp_community.add(peer_community); # doesnt work, incompatible types return true; } and call it like this: add_community([ (11111, 4444), (11111, 5555), (2222, 6666) ]) is it possible? Thank you Jirasek

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Re: Preserving device routes with kernel protocol
by Ondrej Zajicek 17 Apr '12

17 Apr '12

On Tue, Apr 17, 2012 at 11:37:52AM +0100, Howden Nick wrote: > Hi, > > I tried to post this to the mailing list but to no avail. Don't know why it wasn't delivered. > I wonder if you can shed some light on the problem we are having with > devices not being preserved when Bird updates the kernel routing tables. > >birdc show table BIRD > ... > 11.6.9.0/24 via 11.6.1.200 on TAP_One [MYOSPF 16:04] * I (100/10436) > ... > The BIRD table contains the correct network device TAP_One > >ip route ls table NEW > ... > 11.6.9.0/24 via 11.6.1.200 dev TAP_Two proto bird > ... > But, when we inspect the kernel table the network device information has > been lost. Generally, BIRD assumed that IP address is the whole key for gw and iface is derivable from it. With IPv6 and link-local addresses that had to changed, but it probably remained in some parts where it is not relevant to that. I personally never tested this variant. > Tap_One and Tap_Two both have IP addresses in the range 11.6.1.0/24 and I > am relying on the routing tables being correct in order to identify the > correct interface to use for the outbound traffic. The behaviour we are > seeing is the behaviour we expect if routes are added as: > ip route add 11.6.9.0/24 via 11.6.1.200 table NEW > instead of > ip route add 11.6.9.0/24 via 11.6.1.200 dev TAP_One table NEW You are right, for some unknown reason device is not used when route is propagated to the kernel. You could try attached patch. > My understanding was that the "device routes" option would allow the > device part of the routes to be preserved but there is clearly a flaw in > my knowledge. No, that 'device routes' is something completely different - whether device routes (routes without via/gw) are propagated. > Is it actually possible to preserve the device information present in the > BIRD routing tables when they are exported to kernel tables? Try attached patch. -- Elen sila lumenn' omentielvo Ondrej 'SanTiago' Zajicek (email: santiago(a)crfreenet.org) OpenPGP encrypted e-mails preferred (KeyID 0x11DEADC3, wwwkeys.pgp.net) "To err is human -- to blame it on a computer is even more so."

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BGP community not being set on outbound BGP updates
by Lex van Roon 11 Apr '12

11 Apr '12

-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Hi All, I'm building a s/RTBH setup based on bird 1.3.7. I'm using a single route injector which has iBGP peerings with my route-reflector cluster. The setup looks like this (with the injector running on OpenBSD-4.9/Alpha and router* running on Debian Squeeze amd64 if that matters): [injector] / \ / \ / \ [router 1] [router 2] On the injector, I configure static routes, which I export over BGP. I want to tag these prefixes with a BGP community, so I can nullroute the IP's on my route-reflectors and all routers that are connected to this cluster. For this, I'm using the following configuration (only the relevant portions included): [injector] protocol static blacklist { route 1.2.3.4/32 via 192.0.2.1; } protocol bgp router_1 { local 172.16.0.1 as 65000; neighbor 172.16.0.2 as 65000; export filter { bgp_community = -empty-; bgp_community.add((65000,666)); accept; }; import none; } [router 1] protocol bgp injector { local 172.16.0.2 as 65000; neighbor 172.16.0.1 as 65000; export none; import filter { gw = 192.0.2.1; bgp_community = -empty-; bgp_community.add((65000,666)); accept; }; } The configuration for router 2 is identical apart from the IP's, so I haven't included this configuration. This setup works, however, the BGP community only gets set when the prefix enters BGP on router 1: user@injector# birdc show route 1.2.3.4/32 all BIRD 1.3.7 ready. 1.2.3.4/32 via 192.0.2.1 on lo1 [blacklist 12:01] * (200) Type: static unicast univ user@injector# birdc show route export router_1 all BIRD 1.3.7 ready. 1.2.3.4/32 via 192.0.2.1 on lo1 [blacklist 12:01] * (200) Type: static unicast univ BGP.origin: IGP BGP.as_path: BGP.next_hop: 192.0.2.1 BGP.local_pref: 100 user@router_1# birdc show route 1.2.3.4/32 BIRD 1.3.7 ready. 1.2.3.4/32 unreachable [injector 12:01 from 172.16.0.1] * (100) [i] user@router_1# birdc show route 1.2.3.4/32 all BIRD 1.3.7 ready. 1.2.3.4/32 unreachable [injector 12:01 from 172.16.0.1] * (100) [i] Type: BGP unicast univ BGP.origin: IGP BGP.as_path: BGP.next_hop: 192.0.2.1 BGP.local_pref: 100 BGP.community: (65000,666) My questions: 1) First, are these configuration snippets and command output enough to assist in these questions? 2) Is it possible to set a BGP community on a static route which is being exported over BGP? The example in the docs(*) says I should be able to do this. 3) Am i doing something wrong in this setup that is causing the BGP community not being set? 4) Is there a more intelligent way to get this to work? Imho, using a BGP community is the most cleanest and generic way to implement this, but I want this to be set on the injector, and not on my RR cluster. Kind Regards, Lex van Roon *) http://bird.network.cz/?get_doc&f=bird-6.html#ss6.1 - -- LRO-RIPE | 11FCBF2A | 756E 845C 0A88 75FF C750 1E7E 9723 E0DF 11FC BF2A -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.12 (GNU/Linux) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org/ iQEcBAEBAgAGBQJPfZxqAAoJEJcj4N8R/L8q5o8H/2bM1FIfXYtfMsTCsgF5VaeH /jWO1dvBDWpXd6bG/8LO786dboroOgF9u2nN8mMxJdkJ9eurlifs+VkPX53hoTiU 8nT4v1mjF7QzYu6pD3e4U6WDCuvmSSuKFt3F0DI0CBVEI3Gde9RFPT75rC2bfhu2 BOSx8dDmyOpS0WiMuQeqLmfZWwdK12lx7t2/AY1+F2IXCbhC1Q/4sEa8FOEKTLpT ZEPdTBL0N44dqcVaGtfg+FrmsIQi8iIiUrRFhFicxzzEuBuT5jvbbcPWroVg4Hco SSMD1ha9b4b4atWGY/kFa0ixO92aBMtEpJIsCoifd1TUPf3oNwawfjxJdEJkDiA= =y7xa -----END PGP SIGNATURE-----

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bird init state
by Tapio Haapala 08 Apr '12

08 Apr '12

Hello, Is this allready fixed on svn version? With old bird we had problem that some times it leave ospf serrions to init state. With 1.3.5 bird looks that there is still problem that if remote ospf peer get hanged "right way" (on this case guagga node) bird leave session to init state. Naturally this is quagga problem and routes behid that node is dead anyway. BUT looks that if any of ospf sessios are down it can disturb routes from other sessions on same interface. Other sessions on same interface go to 2way/other state and routes are lost also behind of them. So if we have this kind configuration rA ----- rB | SW / \ netC-rC rD - netB | netA And if session to rC hangs to init state it cause that rD go to 2way/other and also routes to netB and netA are lost. On normal state: Router ID Pri State DTime Interface Router IP 10.123.123.99 1 full/other 00:01 eth3 y.y.y.1 10.123.123.211 1 full/other 00:10 eth3 y.y.y.212 10.123.123.1 1 full/other 00:10 eth3 y.y.y.210 y.y.y.102 1 full/dr 00:10 eth3 y.y.y.102 x.x.x.253 1 full/other 00:10 eth3 y.y.y.17 c.c.c.5 1 full/dr 00:09 br70 z.z.z.226 On problem state: Router ID Pri State DTime Interface Router IP 10.123.123.211 1 2way/other 00:10 eth3 y.y.y.212 10.123.123.1 1 init/other 00:09 eth3 y.y.y.210 x.x.x.253 1 full/bdr 00:10 eth3 y.y.y.17 y.y.y.102 1 full/dr 00:10 eth3 y.y.y.102 10.123.123.99 1 2way/other 00:10 eth3 y.y.y.1 c.c.c.5 1 full/bdr 00:10 br70 z.z.z.226 -- F-Solutions Oy Tapio Haapala PL7, 90571 Oulu GSM 0400 998371 Skype burner- IRC Burner@ircnet

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bird under heavy cpu load
by Oleg 07 Apr '12

07 Apr '12

Hi, all. I have some experience with bird under heavy cpu load. I had a situation when bird do frequent updates of kernel table, because of bgp-session frequent down/up (because of cpu and/or net load). I waited about 5-10 minutes for birdc started, when i wanted to reconfigure bird with configure soft command from birdc(ssh and other interactive programs works well). After i changed bird.conf in such a way that i get from upstream 0.0.0.0/0 instead of full view birdc worked fine and bird cpu load lowered(before, bird load cpu about 30-89%). What can i do in such situtation in future for birdc normal work? And additional two questions: Does bird immediately push routes info in kernel table, if it receive routes updates from bgp-peer or it wait for the next kernel table scan? How can i set in one kernel protocol different scan time from another one? Thanks.

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SIGSEGV on rt-prune-step, v1.3.7 and git HEAD
by Henrique de Moraes Holschuh 07 Apr '12

07 Apr '12

I am trying to build a bit more advanced border router here capable of uRPF. For that reason, each eBGP peer gets its own kernel table, and bird is used to feed RST_BGP, RTS_STATIC and RTS_DEVICE routes to these supplementary tables, instead of messing with the "main" kernel routing table. Well, the Linux kernel syncer is not very sturdy ATM: it is prone to leaving behind some routes (which are correctly annotated as proto bird) when you set it to "persist 0". And it also segfaults... It segfaults both in v1.3.7 and git HEAD, so it is not a bug in the new "batched" route flushing code. Here's gdb output for git HEAD (standard hardened Debian build of bird): Starting program: /usr/sbin/bird -c /etc/bird/bird.conf -d -D /tmp/debug -u bird -g birdctl [Thread debugging using libthread_db enabled] Program received signal SIGSEGV, Segmentation fault. 0x000055555555d816 in rt_prune_step (max_feed=<optimized out>, tab=<optimized out>) at ../../nest/rt-table.c:958 958 ../../nest/rt-table.c: No such file or directory. in ../../nest/rt-table.c line 958 of nest/rt-table.c tries to reference e->sender, which apparently can be NULL (whether it *should* be NULL I don't know): rescan: for (e=n->routes; e; e=e->next) if (e->sender->core_state != FS_HAPPY && *** SIGSEGV HERE e->sender->core_state != FS_FEEDING) { if (*max_feed <= 0) { FIB_ITERATE_PUT(fit, fn); return 0; } rte_discard(tab, e); (*max_feed)--; goto rescan; } Any ideas? -- "One disk to rule them all, One disk to find them. One disk to bring them all and in the darkness grind them. In the Land of Redmond where the shadows lie." -- The Silicon Valley Tarot Henrique Holschuh

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Setting MED (?) for a specific BGP route
by Michal Ludvig 07 Apr '12

07 Apr '12

Hi guys I've got a network with two BGP routers (60.234.a.b and 121.98.a.b) with a single upstream ISP for both. I also have an OSPF setup between the routers. Both runing Bird 1.3.4. Each router has a "local" directly attached DMZ subnet (60.234.x.224/28 and 121.98.x.208/28) and exports that to BGP. It also receives the other router's DMZ address through OSPF and re-exports that to BGP as well. I'm not very familiar with BGP but it seems to work pretty well. From outside the traffic to DMZ 60 goes straight to router 60 and the traffic to DMZ 121 goes straight to router 121. Now I moved part of the 60 subnet (one /32 for now) to the 121 DMZ and here's what the routers export: router 60 birdc> show route export bgp_orcon 60.234.x.224/28 dev eth1 [direct1 Mar13] * (240) 60.234.x.236/32 via 172.31.253.2 on tunO2Oorc4 [ospf_eit Mar16] * E2 (150/10/10000) [121.98.a.b] 121.98.x.208/28 via 172.31.253.2 on tunO2Oorc4 [ospf_eit Mar13] * E2 (150/10/10000) [121.98.a.b] router 121 birdc> show route export bgp_orcon 60.234.x.224/28 via 172.31.253.1 on tunO2Oorc4 [ospf_eit Mar13] * E2 (150/10/10000) [60.234.a.b] 60.234.x.236/32 via 121.98.x.221 on vlan121 [kernel1 Mar20] * (10) 121.98.x.208/28 dev vlan121 [direct1 Mar13] * (240) The ISP is happy to accept /32's from us but for some reason traceroute to 60.234.x.236/32 still goes to the router 60 instead of router 121. The ISP suggested to alter MED or prepend our ASN once again to the /32 announcements on the router 60 to give precedence to the router 121. I tried prepending the ASN on router 60 with: export filter { if source = RTS_OSPF then { bgp_path.prepend(64526); } [...] } But that didn't make any difference. Now I've got these questions: 1. How do I alter MED for a specific route on one of the routers? 2. How can I get more details about the exported routes? Like the MED, BGP path, etc? Just to make sure my filters do what I want them to do. Thanks for any pointers! Michal

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v1.3.7 incorrectly tagged in git repository
by Henrique de Moraes Holschuh 05 Apr '12

05 Apr '12

tag v1.3.7 should have been applied to commit 16fc65acc536d3788efe4c0554a2f52699fedc7f "Minor correction". (at least, that's what matches the 1.3.7 tarball). Instead, the tag was applied to HEAD, so it has a few more commits than what is shipped in version 1.3.7. -- "One disk to rule them all, One disk to find them. One disk to bring them all and in the darkness grind them. In the Land of Redmond where the shadows lie." -- The Silicon Valley Tarot Henrique Holschuh

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