January 2018 - Bird-users

Adding more then one bgp community at once
by Борис Коваленко 05 May '23

05 May '23

Hello! Is this possible to add many communites at once? bgp_community.add([(1,1), (1,2)]) is wrong "Setting clist attribute to non-clist value" Regards, Boris -- С уважением, Борис Коваленко

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Bird 1.6.3 removing IPv6 device routes on Linux (3.10.0)
by Ben Arblaster 12 Oct '19

12 Oct '19

Hi, I’m seeing an issue with bird 1.6.3 where IPv6 device routes are unexpectedly removed from the kernel table on Linux (3.10.0, CentOS 7) when bird removes a matching route learned via another protocol (in this case OSPF). To reproduce, I’ve rigged up a very simple test with two bird6 instances running OSPF in a single area 0 over a ptp tunnel. Configs are here - https://gist.github.com/andatche/ca5b5ac120e09b6b8171ec5ca95d2e25 If I add an address/network (e.g. fd00::1/64) to an interface (dummy0) on host A, the route is flooded by A, learned by B and correctly installed in the kernel table on B: fd00::/64 via fe80::5efe:ae2:b006 dev tun0 proto bird metric 1024 If I then add the same address/network (e.g. fd00::1/64) to an interface (dummy0) on host B, at that instant a device route is installed in the kernel table alongside the existing route on host B and it now looks like this: fd00::/64 dev dummy0 proto kernel metric 256 fd00::/64 via fe80::5efe:ae2:b006 dev tun0 proto bird metric 1024 Shortly after, bird picks up the new address/network on dummy0, recalculates the area and correctly selects the connected route as the new best. It then removes the old route via host A from the kernel table, as expected: kernel1 < removed fd00::/64 via fe80::5efe:ae2:b006 on tun0 However, this causes both the route via host A *and* the device route to be removed from the kernel table, leaving the kernel table on host B with no route to fd00::/64 at all. # ip -6 route show fd00::/64 # This is a change in behaviour from 1.4.5 and seems like a bug, rather than the expected behaviour? Regards, Ben -- Ben Arblaster e: ben(a)andatche.com t: +447943860840 w: https://andatche.com

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manipulating the best path, eBGP, MED?
by Thomas＠PhaseHosting 14 Apr '18

14 Apr '18

Supp, I implemented bird in our Private cloud running proxmox to distribute our public address with eBGP to our serverhost. Through iBGP and a ucarp interface i have a HA gateway, the problem is that our host receives the routes but there are multiple entry points to our subnet ( the proxmox hosts). This makes that a diffrent in & out route doenst work. through following link: https://supportforums.cisco.com/document/126691/understanding-bgp-best-path… I learned that my hosts selects its route based on age ( the bird with the first connection is chosen). Can i send a multi-exit discriminator with my eBGP connection to my host? I googled but could find 2 answers that did't change anything: # your default gateway IP below here protocol bgp eBGP { import none; export where proto = "static_packet"; local as 65000; neighbor 10.80.x.x as 65530; password "SECRET"; #med metric 10; #default bgp_med 10; } (offcourse i tried both without # and waited till export) Or is there an other way to make sure that our host routes always to the first server and so on. -- Thomas Valgaeren thomas(a)phasehosting.io +32477915307

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Making a wish ... errr ... *four* wishes! 😳
by Clemens Schrimpe 23 Mar '18

23 Mar '18

Gentlepeople (especially those from the BIRD development team) - being an avid BIRD user for some time now I always kept a small list of „it would be nice, if …“-things for BIRD 1.x, which I kept for myself, as I knew BIRD 2.x was in the works (and thus people were busy already…), but now I get the feeling, that 2.x is slowly stabilizing and I’d like to put them on the table for open discussion: Simple things, a.k.a. low hanging fruits: (Optional) unicast replies to IPv6 RS As one of my many uses for BIRD is in large wireless environments (i.e., IETF meetings) I am very interested in keeping the amount of multicast traffic as low as possible. The standards allow for a router to (immediately) respond with a unicast RA to an RS as an alternative to sending out a multicast RA „some (short, random) time“ after receiving an RS. Many others (Juniper, et.al.) have implemented this and I’d like to see this in BIRD too. The code changes are apparently very simple, so I almost did it myself, but then I didn’t want to interfere with ongoing 2.x developments. (lame excuse, I know …) Context dependent (global) „variables“ for functions/filters I (and probably others too) would really enjoy having more global variables defined for use inside filters & functions, depending on the context within which the respective filter/function is being called. The most obvious ones would be the peer’s (and our own) AS number (in the context of BGP protocols), the filtering direction, the protocol (type and name), the next hop’s address (where applicable), and so on. Yes, I know, most of these could be explicitly given (at least to a function) when calling it as the import/export filter for a protocol with a „where“ clause, but that would defeat the purpose of using templates (which I really do like and use a lot). The general concept of having „globals“ inside functions/filters is already there - just presently only in the context of the route that is being evaluated. I’d like to see this expanded into other contexts as described above. Discuss! 😉😜 More „controversial“ things: Maintain interface addresses (Linux et.al.) It would be nice, if BIRD could be „enhanced“ [sic] to take care of addresses assigned to interfaces, i.e. establish them in the first place and afterwards maintain them, i.e., re-install static, global IPv6 addresses on interfaces, which have suffered a link-state bounce. The latter is particularly interesting, since Linux -by design- removes global IPv6 addresses from an interface during a link-down state transition. Rationale: The various Linux distributions have all sorts of (different and sometimes „funky“) implementations of how to establish addresses to interfaces in the first place and then „deal with them“ during link-state state changes. I would like to have BIRD take care of this relatively simple task as well as the way more complicated task of maintaining millions of routes. If only to have a clean way to define „a router“ within one system (BIRD) as opposed to „get the addresses onto the interfaces with a bunch of iproute2 commands and then start BIRD to take care of the rest“-approach I’ll have to use now. A simple „boot the machine and fire up BIRD - done“ one-stop-shopping solution, if you may. 😉 This is particularly interesting to smaller, dedicated routers, like (former) OpenWRT platforms, Raspberry Pis - or (my application) Ubiquiti routers of all shapes and sizes, where I presently replace the built-in Quagga Version with BIRD. Speaking of Quagga: It takes care of interface addresses too, you know … ;-) An „ipset“ protocol for Linux It would be tremendously helpful to have a protocol, which would maintain given (named) „ipset <http://ipset.netfilter.org/>“ tables on Linux. This would allow for very easy interactions with iptables-based ACLs on Linux platforms. It should/could be treated like a Linux route-table, just with less/different attributes. So it should „sync“, could possibly „import“ items from the ipset, could be made „persistent“, etc. Applications are numerous: From fully automatic BCP38 handling at border interfaces to (again, fully automated) suppression of bogon traffic, to statistical analysis, to … whatever. It would be a single, well defined tool to interact with the whole world of capabilities the iptables/ipsets world offers. If there is any interest in discussing the latter two any further I’d be very happy to spec them out in more detail, of course. Looking forward to hear what people think about these … 😳 Clemens

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Multiple FIBs on FreeBSD
by Azerty32 22 Feb '18

22 Feb '18

Hello, I found one older topic about multiple FIBs on FreeBSD ( http://bird.network.cz/pipermail/bird-users/2013-July/003731.html ). Which status is now about this? BIRD must be running inside Fib0? Sent with [ProtonMail](https://protonmail.com) Secure Email.

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bird 2.0.1: SIGSEGV in nexthop_size
by Svenne Krap 06 Feb '18

06 Feb '18

While trying to setup bird on a new multi-host setup on Arch Linux. We have two routers with two (diverse) directs paths using a /31 (so please ignore the missing broadcast warnings).. At this point we try to get both IPV4 and IPV6 to talk together using both OSPF and BGP. It seems that it is alive for 15 seconds from assert till death... In our handful tries, it is always R1 (and not R2) that dies... (systemd) Journal entries: jan 28 14:59:14 R1 systemd[1]: Started BIRD routing daemon. jan 28 14:59:14 R1 bird[6648]: Missing broadcast address for interface bond0.3670 <<==== due to /31 jan 28 14:59:14 R1 bird[6648]: Missing broadcast address for interface bond0.3671 <<==== due to /31 jan 28 14:59:14 R1 bird[6648]: Started jan 28 14:59:14 R1 bird[6648]: Assertion 'f->addr_type == a->type' failed at nest/rt-fib.c:241 jan 28 14:59:14 R1 bird[6648]: Assertion 'f->addr_type == a->type' failed at nest/rt-fib.c:261 jan 28 14:59:14 R1 bird[6648]: Assertion 'f->addr_type == a->type' failed at nest/rt-fib.c:241 jan 28 14:59:14 R1 bird[6648]: Assertion 'f->addr_type == a->type' failed at nest/rt-fib.c:204 jan 28 14:59:29 R1 bird[6648]: Next hop address 185.38.27.64 is a local address of iface bond0.3670 jan 28 14:59:29 R1 systemd[1]: bird.service: Main process exited, code=dumped, status=11/SEGV jan 28 14:59:29 R1 systemd[1]: bird.service: Failed with result 'core-dump'. GDB from coredump: (gdb) bt #0 nexthop_size (nh=0x48) at ./nest/route.h:601 #1 rta_apply_hostentry (a=0x7ffd3846b5d0, he=0x556b706028c8, mls=0x0) at nest/rt-table.c:1787 #2 0x0000556b6e835f6e in bgp_apply_next_hop (s=0x7ffd3846b6f0, a=0x7ffd3846b5d0, gw=..., ll=...) at proto/bgp/packets.c:767 #3 0x0000556b6e836713 in bgp_decode_nlri (s=s@entry=0x7ffd3846b6f0, afi=afi@entry=65537, nlri=0x556b70603aec "\030\300\250\002\035\n\023:\bP\037\271&\033B\037\271&\033@", '\377' <repeats 16 times>, len=9, ea=ea@entry=0x556b705ff290, nh=<optimized out>, nh_len=4) at proto/bgp/packets.c:2206 #4 0x0000556b6e838dde in bgp_rx_update (conn=conn@entry=0x556b705b6c90, pkt=pkt@entry=0x556b70603ac0 '\377' <repeats 16 times>, len=53) at proto/bgp/packets.c:2306 #5 0x0000556b6e83a51d in bgp_rx_packet (len=<optimized out>, pkt=0x556b70603ac0 '\377' <repeats 16 times>, conn=0x556b705b6c90) at proto/bgp/packets.c:2815 #6 bgp_rx (sk=0x556b70603970, size=<optimized out>) at proto/bgp/packets.c:2860 #7 0x0000556b6e85c44a in call_rx_hook (s=0x556b70603970, size=<optimized out>) at sysdep/unix/io.c:1770 #8 0x0000556b6e85eb57 in sk_read (s=s@entry=0x556b70603970, revents=1) at sysdep/unix/io.c:1858 #9 0x0000556b6e85f5d5 in io_loop () at sysdep/unix/io.c:2318 #10 0x0000556b6e7f493e in main (argc=<optimized out>, argv=<optimized out>) at sysdep/unix/main.c:892 I have the config and both the core file and a binary with debug symbols, that I can send. Svenne

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BIRD 2.0.1 Segmentation fault when configured with merge paths
by Petko Bordjukov 24 Jan '18

24 Jan '18

Hello, Example config file that causes the SEGFAULT: router id 192.168.1.1; protocol kernel { merge paths; ipv6 { export all; }; } Program terminated with signal SIGSEGV, Segmentation fault. #0 0x000056445cef23ea in krt_set_merge_paths (cc=0x0, merge=1, limit=16) at obj/conf/cf-parse.y:819 819 cc->ra_mode = merge ? RA_MERGED : RA_OPTIMAL; (gdb) bt #0 0x000056445cef23ea in krt_set_merge_paths (cc=0x0, merge=1, limit=16) at obj/conf/cf-parse.y:819 #1 0x000056445cefe0d5 in cf_parse () at obj/conf/cf-parse.y:4391 #2 0x000056445cf02d1c in config_parse (c=0x56445ec8b3f0) at conf/conf.c:140 #3 0x000056445cf93b8e in unix_read_config (cp=0x7ffe249d0930, name=0x56445cfb02d4 "bird.conf") at sysdep/unix/main.c:203 #4 0x000056445cf93bd5 in read_config () at sysdep/unix/main.c:213 #5 0x000056445cf94f21 in main (argc=1, argv=0x7ffe249d0a68) at sysdep/unix/main.c:855 (gdb) list 814 krt_set_merge_paths(struct channel_config *cc, uint merge, uint limit) 815 { 816 if ((limit <= 0) || (limit > 255)) 817 cf_error("Merge paths limit must be in range 1-255"); 818 819 cc->ra_mode = merge ? RA_MERGED : RA_OPTIMAL; 820 cc->merge_limit = limit; 821 } 822 823 static void (gdb) Kernel version: Linux edge 4.14.13-1-ARCH #1 SMP PREEMPT Wed Jan 10 11:14:50 UTC 2018 x86_64 GNU/Linux I am able to provide core dump and binary if necessary. Cheers, P.

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[PATCH] Unix IO: Set socket priority after setting family specific options
by Vincent Bernat 23 Jan '18

23 Jan '18

From: Vincent Bernat <vincent(a)bernat.im> On Linux, setting the ToS will also set the priority and the range of accepted values is quite limited (masked by 0x1e). Therefore, 0xc0 is translated to a priority of 0, not something we want, overriding the "7" priority which was set previously explicitely. To avoid that, just move setting priority later in the code. --- sysdep/unix/io.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/sysdep/unix/io.c b/sysdep/unix/io.c index 8773f4c41e86..1c81acbf4518 100644 --- a/sysdep/unix/io.c +++ b/sysdep/unix/io.c @@ -1226,10 +1226,6 @@ sk_setup(sock *s) #endif } - if (s->priority >= 0) - if (sk_set_priority(s, s->priority) < 0) - return -1; - if (sk_is_ipv4(s)) { if (s->flags & SKF_LADDR_RX) @@ -1280,6 +1276,10 @@ sk_setup(sock *s) return -1; } + if (s->priority >= 0) + if (sk_set_priority(s, s->priority) < 0) + return -1; + return 0; } -- 2.15.1

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Community for small IX
by Piotr Marciniak 23 Jan '18

23 Jan '18

Hello, We are running a small IX for around 20 members. A few months ago we moved on Bird and actually I am trying to add some standard communities to prepend or stop annoucing own prefixes to other members but can’t find examples on Bird docs nor by Google. All I found looks limited only to adding fixed community only. I think it is standard and may both work on filters for main table or via pipe import/export filters. But still – I can’t discover how to get and process (to block export) or announce (with prepend) received community. Could you please direct me (or send) some examples how to do this? Thank you, Peter

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Re: Community for small IX - problem with 4B ASN
by Piotr Marciniak 23 Jan '18

23 Jan '18

Dear Advisors ;], Thank you for all posts. But still I do not know how to make Bird working with 4B communities and if I may do this - whether it will be accepted for our peers? In short - I do not know how to adapt to 4B communities following examples: https://gitlab.labs.nic.cz/labs/bird/wikis/Route_server_with_community_base… https://gitlab.labs.nic.cz/labs/bird/wikis/Route_server_with_community_base… Is there any way to enable 4B communities in bird.conf? I do not have any problem with 4B ASn. I set bgp peering sessions from Bird with 4B ASn. Even our IX has AS205082. This is why I put 2 questions: 1. Is it possible to enable 4B ASn for communities in Bird? Will it work with other rouers? 2. Can we use instead private ASn just for community filters? Are they processed corretly by other Internet routers of our peers? Please - do not explain me theoretical difference between 16 and 32 bits. Question is simple - can I use 4B communities for filters? If not - what 16bit "fake ASn" I can use instead safely? Best wishes, Piotr Marciniak -----Oryginalna wiadomość----- From: Paweł Nastachowski Sent: Monday, January 22, 2018 1:12 PM To: Piotr Marciniak Cc: bird-users(a)network.cz Subject: Re: Community for small IX - problem with 4B ASN Hi Piotr, I should use extended community for 4B ASN, because normal community is too small “Encodes a 32-bit value displayed as “16-bit ASN:16-bit value”. Regards, Pawel -----Wiadomość oryginalna----- Od: Bird-users <bird-users-bounces(a)network.cz> w imieniu użytkownika Piotr Marciniak <zboj(a)mnc.pl> Data: poniedziałek, 22 stycznia 2018 11:15 Do: "bird-users(a)network.cz" <bird-users(a)network.cz> Temat: Community for small IX - problem with 4B ASN Hello, I've spent a while on below docs and faced a problem with 4B ASN we use. Bird reports an error 'when 'myas' is 4B => so above 65535. See some testing example below: bird> configure Reading configuration from /etc/bird/bird.conf /etc/bird/bird.conf, line 81: Value 165250 out of range (0-65535) The only way this config reports no error is to set here private ASn - fe. 65250. But it will never match our real ASn. Two questions: 1. Is it possible to enable 4B ASn for communities in Bird? Will it work with other rouers? 2. Can we use instead private ASn just for community filters? Are they processed corretly by other Internet routers of our peers? Or maybe there is another work around? Best wishes, Peter -----Oryginalna wiadomość----- From: Piotr Marciniak Sent: Friday, December 29, 2017 5:01 PM To: Ondrej Zajicek Cc: bird-users(a)network.cz Subject: Re: Community for small IX There are some examples in BIRD wiki, mainly: https://urldefense.proofpoint.com/v2/url?u=https-3A__gitlab.labs.nic.cz_lab… https://urldefense.proofpoint.com/v2/url?u=https-3A__gitlab.labs.nic.cz_lab… -- 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." This email is from Equinix (EMEA) B.V. or one of its associated companies in the territory from where this email has been sent. This email, and any files transmitted with it, contains information which is confidential, is solely for the use of the intended recipient and may be legally privileged. If you have received this email in error, please notify the sender and delete this email immediately. Equinix (EMEA) B.V.. Registered Office: Amstelplein 1, 1096 HA Amsterdam, The Netherlands. Registered in The Netherlands No. 57577889.

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