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Question about filter with BGP Communities and BGP Extended Communities
by Lucenildo Lins Aquino Júnior 28 Oct '16

28 Oct '16

Hi All, I am run bird for lab and I am with a difficult to create a filter with bgp communities and bgp extended communities. In my filter at first I check if router need go only for peer ASN, note that is a export filter. If not only for peer ASN and have only-community (65001:* or ro:65001:*) drop this route. I was executed troubleshooting and I could determinate that problem is in this operation: "(([(65001,*)] ~ bgp_community) || ([(ro,65001,*)] ~ bgp_ext_community))". I think in this regular expression have a problem, that case create a fault in my if-clause. I operate my bird in mode router-server, to simulate a IXP. In this test my other client announce a router without community 65001:*. and in import filter with ASN 61580 I am accept all routes . Thanks, Lucenildo Lins +++++++ lucenildo@other-client> show route advertising-protocol bgp 187.16.213.253 extensive 168.181.23.0/24 inet.0: 27 destinations, 32 routes (26 active, 0 holddown, 2 hidden) * 168.181.23.0/24 (1 entry, 1 announced) BGP group IX-emulado-v4 type External Nexthop: Self AS path: [61580] I Communities: 61580:5571 65000:11752 65000:14026 +++++++++ define Client_ASN = 65551; filter bgp_out_as65551 { if exp_only(Client_ASN) then { rm_interal_comm(); accept; } if exp_has_only() then { rm_interal_comm(); reject; } rm_interal_comm(); accept; } function exp_has_only() { if !(source = RTS_BGP) then return false; if (([(65001,*)] ~ bgp_community) || ([(ro,65001,*)] ~ bgp_ext_community)) then return true; return false; } function exp_only(int ASNumber) { if ! (source = RTS_BGP) then return false; if ASNumber > 65535 then { if (ro,65001,ASNumber) ~ bgp_ext_community then return true; } else { if (((65001,ASNumber) ~ bgp_community) || ((ro,65001,ASNumber) ~ bgp_ext_community)) then return true; } return false; }

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Bird6 picking up /128 routes from the routing cache
by Tore Anderson 24 Oct '16

24 Oct '16

Hi, I noticed something a bit spooky in my lab. Bird6 appears to pick up and export routes that are added to the Linux kernel's routing cache. That is, with a bird6.conf as shown below, if I fire up bird6 in debug mode, and ping a destination with a reduced MTU (to get an ICMPv6 PTB back to trigger caching of the host route due to its lower PMTU): $ ping6 -M do -s 1452 2a01:79d:1234:: # Norwegian ISP using 6RD PING 2a01:79d:1234::(2a01:79d:1234::) 1452 data bytes >From 2a01:798:0:416::a1b:1 icmp_seq=1 Packet too big: mtu=1480 I see the following show up in bird6's stderr: $ /usr/sbin/bird6 -d -u bird -g bird bird: Started bird: Exporting external route ::/0; next-hop=fe80::e611:5bff:fe9b:90e1; source=kernel1 bird: Exporting external route 2a01:79d:1234::/128; next-hop=fe80::e611:5bff:fe9b:90e1; source=kernel1 This route does however *not* show up in Linux' "main" routing table, only in the cache one: $ ip -6 route show table cache 2a01:79d:1234:: via fe80::e611:5bff:fe9b:90e1 dev eth0 metric 0 cache expires 28sec mtu 1480 hoplimit 64 I've seen this both with bird 1.5.0 and 1.6.2, and on Ubuntu kernels 3.13.0 and 4.4.0. Question is, why does this happen? I certainly wouldn't expect it to and if it means that this router would start attracting traffic destined for the host in question I fear it'll create a blackhole/loop. If I change the kernel table number from 254 ("main") to some other random table number, it doesn't happen anymore. To complicate matters further I only see this in my lab. Even though I have the same versions and config in production I cannot see that the same thing happens there. One difference I can think of is that in production the default route is learned from OSPF while in the lab it is learned from SLAAC (and picked up by bird6 that way as shown in the debug output). Not sure if that makes any difference (and if so why). Tore $ cat /etc/bird/bird6.conf router id 192.0.2.1; protocol device {} protocol kernel { learn; export all; import all; kernel table 254; # "main" } protocol ospf { export filter { printn "Exporting external route "; printn net; if defined(gw) then { printn "; next-hop="; printn gw; } if defined(proto) then { printn "; source="; printn proto; } print ""; accept; }; area 0.0.0.0 { interface "eth0" { type broadcast; }; }; }

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BLACKHOLE community RFC7999
by Alexander Shikov 21 Oct '16

21 Oct '16

Hi! Just FYI: https://www.rfc-editor.org/rfc/rfc7999.txt I guess this feature deserves to be implemented. -- Alexander Shikov Technical Staff, Digital Telecom IX http://dtel-ix.net/

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Re: Out of memory crash of 3000 routes in BGP
by Madhu 21 Oct '16

21 Oct '16

Looks like the problem is still there. I used 1.6.0 and also 1.6.2. On Mon, Oct 10, 2016 at 10:56 AM, james machado <hvgeekwtrvl(a)gmail.com> wrote: > Madhu check out the following thread. http://bird.network.cz/ > pipermail/bird-users/2016-September/010578.html > > > > On Mon, Oct 10, 2016 at 10:02 AM, Madhu <informmadhu(a)gmail.com> wrote: > >> Hi, >> >> I am seeing a out of memory crash with 3000 routes in BGP. Is this a >> known issue? I m seeing this issue in 1.6.0 and 1.6.2 . >> >> >> [ 1098.912753] Call Trace: >> [ 1098.915481] [<ffffffff81b96521>] dump_stack+0x64/0x82 >> [ 1098.921225] [<ffffffff81b91a46>] dump_header+0x7f/0x1f1 >> [ 1098.927163] [<ffffffff810b3e76>] ? put_online_cpus+0x56/0x80 >> [ 1098.933587] [<ffffffff811110ac>] ? rcu_oom_notify+0xcc/0xf0 >> [ 1098.939914] [<ffffffff811a2735>] oom_kill_process+0x205/0x360 >> [ 1098.946435] [<ffffffff814595b5>] ? security_capable_noaudit+0x15/0x20 >> [ 1098.953733] [<ffffffff811a2ee2>] out_of_memory+0x492/0x4d0 >> [ 1098.959962] [<ffffffff811a8f30>] __alloc_pages_nodemask+0xa00/0xb60 >> [ 1098.967067] [<ffffffff811eb1fa>] alloc_pages_vma+0x9a/0x160 >> [ 1098.973393] [<ffffffff811cd5c8>] handle_mm_fault+0xd38/0x1080 >> [ 1098.979914] [<ffffffff811d4b74>] ? change_protection+0x594/0x850 >> [ 1098.986726] [<ffffffff8109f5ae>] __do_page_fault+0x19e/0x560 >> [ 1098.993149] [<ffffffff811d4f81>] ? mprotect_fixup+0x151/0x290 >> [ 1098.999669] [<ffffffff8109f9a1>] do_page_fault+0x31/0x70 >> [ 1099.005704] [<ffffffff81ba40e8>] page_fault+0x28/0x30 >> >> Madhu >> > >

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bird 1.6.2 rpm
by Alex Dodson 18 Oct '16

18 Oct '16

Hello, We are using bird on RHEL7. When trying to update from the rpm we get the following errors. Failed to check for updates with the following error message: Failed to build transaction: bird-1.6.2-1.x86_64 requires libncurses.so.6()(64bit) bird-1.6.2-1.x86_64 requires libtinfo.so.6()(64bit) Is there a specific reason to build against the more modern non baseline version of ncurses for RHEL7 or am I fine to rebuild this and deploy it with it built against ncurses 5.9 which is included with RHEL7? Thanks for your assistance. Alex

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Bird upgrade kills all sessions for minutes.
by Alexander Morlang 14 Oct '16

14 Oct '16

Hi, We are using bird als a routing daemon in a meshed ethernet fabric. Bird runs on the connected hosts as well as on the network equipment to archive full layer 3 connectivity. When we upgrade the installed packages on the Hosts, the upgrade process stops bird, does upgrades and starts bird again. These behavior lead to a loss of connectivity for one up to several minutes, which make the upgrade process very disruptive. Usually, i would expect an upgrade and a restart of the daemon after the upgrade, which would keep the time in which the host is offline rather short. Following questions arise: * is this behavior intended, or is it a unintended side effect? * did you consider this type of setups, when you implemented the upgrade process this disruptive? * Can you consider to fix it, easing the upgrade process in this type of setups? In our careful evaluation, we think, using the -R parameter of dh_installinit could ease our suffering, resulting in following patch: diff -ruN bird-1.6.2.old/debian/rules bird-1.6.2/debian/rules --- bird-1.6.2.old/debian/rules 2016-09-29 20:49:00.000000000 +0200 +++ bird-1.6.2/debian/rules 2016-10-11 10:27:00.717429976 +0200 @@ -69,8 +69,8 @@ dh_strip -O--dbgsym-migration='bird-dbg (<< 1.6.0-2~), bird-bgp-dbg (<< 1.6.0-2~)' override_dh_installinit: - dh_installinit --name=bird - dh_installinit --name=bird6 + dh_installinit --name=bird -R + dh_installinit --name=bird6 -R DB2MAN = /usr/share/sgml/docbook/stylesheet/xsl/nwalsh/manpages/docbook.xsl XP = xsltproc -''-nonet -''-param man.charmap.use.subset "0" Regards, Alexander Morlang ------ SysEleven GmbH Ohlauer Straße 43 10999 Berlin T +49 30 233 2012 0 F +49 30 616 7555 0 http://www.syseleven.de http://www.facebook.com/SysEleven Aktueller System-Status immer unter: http://www.twitter.com/syseleven Firmensitz: Berlin Registergericht: AG Berlin Charlottenburg, HRB 108571 B Geschäftsführer: Marc Korthaus, Jens Ihlenfeld

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bird-1.6.2 rpm
by Roman Romanyak 13 Oct '16

13 Oct '16

Hello bird users, is there bird-1.6.2 rpm available? The latest versin at bird.network.cz is bird-1.6.0-1. Thanks!

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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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Out of memory crash of 3000 routes in BGP
by Madhu 10 Oct '16

10 Oct '16

Hi, I am seeing a out of memory crash with 3000 routes in BGP. Is this a known issue? I m seeing this issue in 1.6.0 and 1.6.2 . [ 1098.912753] Call Trace: [ 1098.915481] [<ffffffff81b96521>] dump_stack+0x64/0x82 [ 1098.921225] [<ffffffff81b91a46>] dump_header+0x7f/0x1f1 [ 1098.927163] [<ffffffff810b3e76>] ? put_online_cpus+0x56/0x80 [ 1098.933587] [<ffffffff811110ac>] ? rcu_oom_notify+0xcc/0xf0 [ 1098.939914] [<ffffffff811a2735>] oom_kill_process+0x205/0x360 [ 1098.946435] [<ffffffff814595b5>] ? security_capable_noaudit+0x15/0x20 [ 1098.953733] [<ffffffff811a2ee2>] out_of_memory+0x492/0x4d0 [ 1098.959962] [<ffffffff811a8f30>] __alloc_pages_nodemask+0xa00/0xb60 [ 1098.967067] [<ffffffff811eb1fa>] alloc_pages_vma+0x9a/0x160 [ 1098.973393] [<ffffffff811cd5c8>] handle_mm_fault+0xd38/0x1080 [ 1098.979914] [<ffffffff811d4b74>] ? change_protection+0x594/0x850 [ 1098.986726] [<ffffffff8109f5ae>] __do_page_fault+0x19e/0x560 [ 1098.993149] [<ffffffff811d4f81>] ? mprotect_fixup+0x151/0x290 [ 1098.999669] [<ffffffff8109f9a1>] do_page_fault+0x31/0x70 [ 1099.005704] [<ffffffff81ba40e8>] page_fault+0x28/0x30 Madhu

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Fwd: ECMP BGP issue of more than 16 paths
by Madhu 07 Oct '16

07 Oct '16

Hi, I have an issue with bird routing daemon where I have EBGP between S1 and S2 with 62 paths. I am able to learn all the BGP routes with 62 paths in bird. But the kernel only showing 16 paths. I configured “merge paths 255” under protocol kernel, but still it shows only 16 paths. Can somebody help me with this? 120.100.104.96/28 via 100.1.2.0 on br1003 [AG1-CR1-link0 17:06:48] * (100) [i] via 100.1.62.0 on br1063 [AG1-CR1-link61 17:07:14] (100) [i] via 100.1.59.0 on br1060 [AG1-CR1-link58 17:07:14] (100) [i] via 100.1.57.0 on br1058 [AG1-CR1-link56 17:07:14] (100) [i] via 100.1.56.0 on br1057 [AG1-CR1-link55 17:07:12] (100) [i] via 100.1.55.0 on br1056 [AG1-CR1-link54 17:07:12] (100) [i] via 100.1.54.0 on br1055 [AG1-CR1-link53 17:07:12] (100) [i] via 100.1.53.0 on br1054 [AG1-CR1-link52 17:07:12] (100) [i] via 100.1.52.0 on br1053 [AG1-CR1-link51 17:07:10] (100) [i] via 100.1.50.0 on br1051 [AG1-CR1-link49 17:07:10] (100) [i] via 100.1.47.0 on br1048 [AG1-CR1-link46 17:07:10] (100) [i] via 100.1.46.0 on br1047 [AG1-CR1-link45 17:07:10] (100) [i] via 100.1.45.0 on br1046 [AG1-CR1-link44 17:07:08] (100) [i] via 100.1.44.0 on br1045 [AG1-CR1-link43 17:07:08] (100) [i] via 100.1.42.0 on br1043 [AG1-CR1-link41 17:07:08] (100) [i] via 100.1.41.0 on br1042 [AG1-CR1-link40 17:07:08] (100) [i] via 100.1.37.0 on br1038 [AG1-CR1-link36 17:07:04] (100) [i] via 100.1.35.0 on br1036 [AG1-CR1-link34 17:07:04] (100) [i] via 100.1.34.0 on br1035 [AG1-CR1-link33 17:07:04] (100) [i] via 100.1.32.0 on br1033 [AG1-CR1-link31 17:07:04] (100) [i] via 100.1.31.0 on br1032 [AG1-CR1-link30 17:07:01] (100) [i] via 100.1.30.0 on br1031 [AG1-CR1-link29 17:07:01] (100) [i] via 100.1.29.0 on br1030 [AG1-CR1-link28 17:07:01] (100) [i] via 100.1.27.0 on br1028 [AG1-CR1-link25 17:07:01] (100) [i] via 100.1.26.0 on br1027 [AG1-CR1-link24 17:06:57] (100) [i] via 100.1.25.0 on br1026 [AG1-CR1-link23 17:06:57] (100) [i] via 100.1.21.0 on br1022 [AG1-CR1-link19 17:06:57] (100) [i] via 100.1.19.0 on br1020 [AG1-CR1-link17 17:06:57] (100) [i] via 100.1.18.0 on br1019 [AG1-CR1-link16 17:06:54] (100) [i] via 100.1.17.0 on br1018 [AG1-CR1-link15 17:06:54] (100) [i] via 100.1.15.0 on br1016 [AG1-CR1-link13 17:06:54] (100) [i] via 100.1.13.0 on br1014 [AG1-CR1-link11 17:06:54] (100) [i] via 100.1.12.0 on br1013 [AG1-CR1-link10 17:06:51] (100) [i] via 100.1.9.0 on br1010 [AG1-CR1-link7 17:06:51] (100) [i] via 100.1.7.0 on br1008 [AG1-CR1-link5 17:06:51] (100) [i] via 100.1.5.0 on br1006 [AG1-CR1-link3 17:06:51] (100) [i] via 100.1.3.0 on br1004 [AG1-CR1-link1 17:04:43] (100) [i] via 100.1.63.0 on br1064 [AG1-CR1-link62 17:05:54] (100) [i] via 100.1.61.0 on br1062 [AG1-CR1-link60 17:05:54] (100) [i] via 100.1.60.0 on br1061 [AG1-CR1-link59 17:05:54] (100) [i] via 100.1.58.0 on br1059 [AG1-CR1-link57 17:05:49] (100) [i] via 100.1.51.0 on br1052 [AG1-CR1-link50 17:05:49] (100) [i] via 100.1.49.0 on br1050 [AG1-CR1-link48 17:05:49] (100) [i] via 100.1.48.0 on br1049 [AG1-CR1-link47 17:05:49] (100) [i] via 100.1.43.0 on br1044 [AG1-CR1-link42 17:05:43] (100) [i] via 100.1.40.0 on br1041 [AG1-CR1-link39 17:05:43] (100) [i] via 100.1.39.0 on br1040 [AG1-CR1-link38 17:05:43] (100) [i] via 100.1.38.0 on br1039 [AG1-CR1-link37 17:05:43] (100) [i] via 100.1.36.0 on br1037 [AG1-CR1-link35 17:05:39] (100) [i] via 100.1.33.0 on br1034 [AG1-CR1-link32 17:05:39] (100) [i] via 100.1.28.0 on br1029 [AG1-CR1-link27 17:05:39] (100) [i] via 100.1.24.0 on br1025 [AG1-CR1-link22 17:05:39] (100) [i] via 100.1.23.0 on br1024 [AG1-CR1-link21 17:05:36] (100) [i] via 100.1.22.0 on br1023 [AG1-CR1-link20 17:05:36] (100) [i] via 100.1.20.0 on br1021 [AG1-CR1-link18 17:05:36] (100) [i] via 100.1.16.0 on br1017 [AG1-CR1-link14 17:05:36] (100) [i] via 100.1.14.0 on br1015 [AG1-CR1-link12 17:05:35] (100) [i] via 100.1.11.0 on br1012 [AG1-CR1-link9 17:05:35] (100) [i] via 100.1.10.0 on br1011 [AG1-CR1-link8 17:05:35] (100) [i] via 100.1.8.0 on br1009 [AG1-CR1-link6 17:05:35] (100) [i] via 100.1.6.0 on br1007 [AG1-CR1-link4 17:05:35] (100) [i] via 100.1.4.0 on br1005 [AG1-CR1-link2 17:05:35] (100) [i] # ip route list 120.100.104.96/28 120.100.104.96/28 proto bird nexthop via 100.1.2.0 dev br1003 weight 1 nexthop via 100.1.3.0 dev br1004 weight 1 nexthop via 100.1.4.0 dev br1005 weight 1 nexthop via 100.1.5.0 dev br1006 weight 1 nexthop via 100.1.6.0 dev br1007 weight 1 nexthop via 100.1.7.0 dev br1008 weight 1 nexthop via 100.1.8.0 dev br1009 weight 1 nexthop via 100.1.9.0 dev br1010 weight 1 nexthop via 100.1.10.0 dev br1011 weight 1 nexthop via 100.1.11.0 dev br1012 weight 1 nexthop via 100.1.12.0 dev br1013 weight 1 nexthop via 100.1.13.0 dev br1014 weight 1 nexthop via 100.1.14.0 dev br1015 weight 1 nexthop via 100.1.15.0 dev br1016 weight 1 nexthop via 100.1.16.0 dev br1017 weight 1 nexthop via 100.1.17.0 dev br1018 weight 1 router id 100.0.2.1; log syslog all; protocol kernel { scan time 60; import all; merge paths 255; export all; # Actually insert routes into the kernel routing table } Thanks, Madhu

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