May 2018 - Bird-users - Mailing Lists

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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Bug: BFD confuses sessions with identical IPv6 link-local addresses
by Julian Brost 14 Jan '21

14 Jan '21

Hi, I just tried to enable BFD for some OSPF and BGP connections and ran into an issue which BFD sessions flapping up and down and Bird logging many messages like these: bfd1: Bad packet from fe80::2 - unknown session id (130079069) bfd1: Bad packet from fe80::2 - unknown session id (3102513000) bfd1: Bad packet from fe80::2 - unknown session id (3650438750) bfd1: Bad packet from fe80::2 - unknown session id (1597034259) This presumably happens due to this piece of code in bfd_rx_hook() in proto/bfd/packets.c: s = bfd_find_session_by_addr(p, sk->faddr); I use fe80::1/fe80::2 as addresses for most of my IPv6 peering connections and sk->faddr is just a 128 bit value, so it contains no interface identifier, which likely leads to Bird confusing multiple BFD sessions. Regards, Julian

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[PATCH] babel: Set onlink flag for IPv4 routes with unreachable next hop
by Toke Høiland-Jørgensen 14 Apr '20

14 Apr '20

If the next hop of a route is not a reachable address, the route should be installed as onlink. This enables a configuration common in mesh networks where the mesh interface is assigned a /32 and babel handles the routing by installing onlink routes. Signed-off-by: Toke Høiland-Jørgensen <toke(a)toke.dk> --- proto/babel/babel.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/proto/babel/babel.c b/proto/babel/babel.c index 88c4711e..4fd88042 100644 --- a/proto/babel/babel.c +++ b/proto/babel/babel.c @@ -640,6 +640,13 @@ babel_announce_rte(struct babel_proto *p, struct babel_entry *e) .nh.iface = r->neigh->ifa->iface, }; + /* If we cannot find a reachable neighbour, set the entry to be onlink. This + * makes it possible to, e.g., assign /32 addresses on a mesh interface and + * have routing work. + */ + if (!neigh_find2(&p->p, &r->next_hop, r->neigh->ifa->iface, 0)) + a0.nh.flags = RNF_ONLINK; + rta *a = rta_lookup(&a0); rte *rte = rte_get_temp(a); rte->u.babel.seqno = r->seqno; -- 2.17.0

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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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route withdrawals are not sent upon protocol removal
by Thomás S. Bregolin 08 Jul '18

08 Jul '18

Hello, bird (all versions) does not send BGP route withdrawals when a protocol is removed, only when the filter changes or the protocol is disabled. Is this intentional? If not, could it be a configurable option to send route withdrawals upon protocols being removed? I am having an issue where the peers keep stale routes that were removed from bird but were not withdrawn via update messages. Regards, Thomás

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BIRD - Config Support for RFC 3107 - Carrying Label Information in BGP
by LAKSHMANAN, THIRUVAZHIYA 30 Jun '18

30 Jun '18

Dear support-team, In the BIRD 2.0 user guide, I see the support for RFC 3107 - Carrying Label information in BGP. We want to configure a VM with BIRD agent working like a PE for adding MPLS labels for IPv4 and IPv6 unicast routes. Do we have this configuration supported now, and can I get any sample working configuration for this please. Regards, Thiruvazhiyan

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BGP origin attribute
by Arvin Gan 01 Jun '18

01 Jun '18

Hi All, I notice the origin attribute in function bgp_update_attrs , if route source is BGP, I think it should set as ORIGIN_IGP, not INCOMPLETE, according to RFC or Cisco device . It seems there is mistake on Line 1443 in attrs.c . Line 1443: bgp_set_attr_u32(&attrs, pool, BA_ORIGIN, 0, src ? ORIGIN_INCOMPLETE : ORIGIN_IGP); ð bgp_set_attr_u32(&attrs, pool, BA_ORIGIN, 0, src ? ORIGIN_IGP : ORIGIN_INCOMPLETE ); // correct? Thanks Arvin

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bgp_next_hop check?
by Job Snijders 29 May '18

29 May '18

Dear BIRD devs, On https://gitlab.labs.nic.cz/labs/bird/wikis/BGP_filtering I see the following curious snippet: function xx() { ... if bgp_next_hop != from then return false; ... } What in the above example does "from" mean? Is "from" some kind of magic keyword that expands into something? Kind regards, Job

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Static route bgp_next_hop attribute.
by oldnick nsp 29 May '18

29 May '18

Hi all! I'm trying to use Bird to announce route with predefined bgp next hop and to avoid filter manipulation on this route to set next-hop on it. My goal is to put route configuration into separate include file with fewer lines as possible. Relevant part of my config is as follows: protocol bgp 'test_nbr' { local as 65001; neighbor 10.0.0.2 as 65002; hold time 30; multihop 5; import all; export all; next hop keep; } protocol static test { route 192.168.0.1/32 blackhole { bgp_next_hop = 172.16.0.1; }; } I can see that route has bgp_next_hop attribute with command "show route all": bird> show route all 192.168.0.1/32 blackhole [test 07:05:07] * (200) Type: static unicast univ BGP.next_hop: 172.16.0.1 But when neighbor receives this announce, it still gets the peer address as a next-hop. This is debug output at neighbor side: *May 29 14:05:02.327: BGP(0): 10.0.0.1 rcvd UPDATE w/ attr: nexthop 10.0.0.1, origin i, merged path 65001, AS_PATH *May 29 14:05:02.331: BGP(0): 10.0.0.1 rcvd 192.168.0.1/32 So, the question is: is there any way to keep bgp_next_hop attribute from static route into protocol bgp announces? -- Regards, Sergey

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BGP Monitoring Protocol (BMP) support in Bird?
by Emerson Barea 29 May '18

29 May '18

Hi, is there BGP Monitoring Protocol support in Bird? I didn't get this information in Bird docs. Thank you. Tocha.

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