October 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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Static routes and BFD
by J. Kendzorra 31 Oct '16

31 Oct '16

Hello all, I am trying to make use of BFD for default gateway failover (in my BFD test bed). I used multiple variations, but according to the documentation (if I get it right), I should be fine using something like this: ,-- on client: # empty BFD config protocol bfd { #debug all; } # simple default route with BFD driven failover protocol static { debug all; route 0.0.0.0/0 via 192.168.1.1 { bfd on; }; route 0.0.0.0/0 via 192.168.1.2 { bfd on; }; }; `-- ,-- on gateways: protocol bfd { interface "vlan*" { passive; }; debug all; } `-- Whenever I omit the "passive" statement, I can see "BFDv1 Control State Down" going on the wire; not sure why this appears to be the default on how to change this to "up": ,-- tcpdump: 08:11:41.732031 IP 192.168.1.3.23863 > 192.168.1.2.3784: BFDv1, Control, State Down, Flags: [none], length: 24 08:11:41.732033 ethertype IPv4, IP 192.168.1.3.23863 > 192.168.1.2.3784: BFDv1, Control, State Down, Flags: [none], length: 24 08:11:41.732034 ethertype IPv4, IP 192.168.1.3.23863 > 192.168.1.2.3784: BFDv1, Control, State Down, Flags: [none], length: 24 `-- What puzzles me is that I'd now expect the client to initiate a BFD connection to both gateways, however I do not see a single packet (except when not using passive I see what's pasted above). The config appears to get active however: ,-- 2016-10-26 08:07:37 <INFO> Reconfiguring 2016-10-26 08:07:37 <TRACE> bfd1: Session to 192.168.1.1 reconfigured 2016-10-26 08:07:37 <TRACE> bfd1: Session to 192.168.1.2 reconfigured 2016-10-26 08:07:37 <TRACE> bfd1: Reconfigured 2016-10-26 08:07:37 <TRACE> static1: Reconfigured 2016-10-26 08:07:37 <INFO> Reconfigured `-- This is what I see when BFD is not configured to be passive: ,-- 2016-10-26 08:11:58 <TRACE> bfd1: Sending CTL to 192.168.1.2 [Down] 2016-10-26 08:11:58 <TRACE> bfd1: Sending CTL to 192.168.1.1 [Down] (...) `-- Any clues on how to debug this further? Thanks, J.

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[PATCH] fix syslog corruption when using customized name
by Chris Caputo 31 Oct '16

31 Oct '16

Fix bug with syslog using string passed to openlog() which is later stomped on, resulting in corrupted log messages. This happens when name is specified in a syslog log line, ala: log syslog name "bird-foo" all; Per Linux SYSLOG(3): The argument ident in the call of openlog() is probably stored as-is. Thus, if the string it points to is changed, syslog() may start prepending the changed string, and if the string it points to ceases to exist, the results are undefined. Most portable is to use a string constant. Signed-off-by: : Chris Caputo <ccaputo(a)alt.net> --- sysdep/unix/log.c | 12 +++++++++--- 1 file changed, 9 insertions(+), 3 deletions(-) diff --git a/sysdep/unix/log.c b/sysdep/unix/log.c index 1fd6442..7086f7d 100644 --- a/sysdep/unix/log.c +++ b/sysdep/unix/log.c @@ -289,17 +289,23 @@ log_switch(int debug, list *l, char *new_syslog_name) #ifdef HAVE_SYSLOG char *old_syslog_name = current_syslog_name; - current_syslog_name = new_syslog_name; if (old_syslog_name && new_syslog_name && !strcmp(old_syslog_name, new_syslog_name)) return; if (old_syslog_name) - closelog(); + { + closelog(); + free(old_syslog_name); + } if (new_syslog_name) - openlog(new_syslog_name, LOG_CONS | LOG_NDELAY, LOG_DAEMON); + { + current_syslog_name = xmalloc(strlen(new_syslog_name) + 1); + strcpy(current_syslog_name, new_syslog_name); + openlog(current_syslog_name, LOG_CONS | LOG_NDELAY, LOG_DAEMON); + } #endif }

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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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