September 2017 - Bird-users

Set interfaces in BIRD
by Александра Урошевска 21 Sep '17

21 Sep '17

Hello everybody, I am a student from Macedonia at FINKI <https://www.finki.ukim.mk/en>. I am 24 years old. I just installed BIRD on a VM and I want to know how to set up interfaces and protocols. I am very new at this, want to try how it works. Can anybody help me? Thank you very much. Best regards, Aleksandra

2 1

Ignoring bogus route 240.0.0.0/4
by Alexander Demenshin 20 Sep '17

20 Sep '17

Hi, Any reason why 240.0.0.0/4+ routes are ignored by bird (1.6.3)? I have tried to blackhole this range in static protocol, but got this message. Attempts to manually add any kernel route from this range were silently ignored. -- With best regards, Alexander.

4 6

[RFC,PATCH 1/2] BGP: Implement iebgp_peer mode.
by Lennert Buytenhek 20 Sep '17

20 Sep '17

Implement an 'internal eBGP' peer mode, where the remote peer uses a different AS number than we do, as if it were an eBGP peer, but we treat the peer as if were an AS-internal peer. This enables implementing a network setup according to the model documented in RFC7938. This makes two changes to the BGP route propagation logic: * When we are propagating a route to or from an internal eBGP peer, we will avoid resetting the MED attribute. * When comparing BGP-learned routes, we will consider routes learned from an 'internal eBGP' peer as iBGP routes as far as the RFC 4271 9.1.2.2. d) check (Prefer external peers) is concerned. --- proto/bgp/attrs.c | 22 ++++++++++++++++------ proto/bgp/bgp.h | 1 + proto/bgp/config.Y | 4 +++- 3 files changed, 20 insertions(+), 7 deletions(-) diff --git a/proto/bgp/attrs.c b/proto/bgp/attrs.c index b9e2490d..478c805c 100644 --- a/proto/bgp/attrs.c +++ b/proto/bgp/attrs.c @@ -1100,15 +1100,21 @@ bgp_update_attrs(struct bgp_proto *p, rte *e, ea_list **attrs, struct linpool *p if (!p->is_internal && !p->rs_client) { + struct bgp_proto *new_bgp = (e->attrs->src->proto->proto == &proto_bgp) ? + (struct bgp_proto *) e->attrs->src->proto : NULL; + bgp_path_prepend(e, attrs, pool, p->local_as); /* The MULTI_EXIT_DISC attribute received from a neighboring AS MUST NOT be * propagated to other neighboring ASes. * Perhaps it would be better to undefine it. */ - a = ea_find(e->attrs->eattrs, EA_CODE(EAP_BGP, BA_MULTI_EXIT_DISC)); - if (a) - bgp_attach_attr(attrs, pool, BA_MULTI_EXIT_DISC, 0); + if (!p->cf->iebgp_peer && (new_bgp == NULL || !new_bgp->cf->iebgp_peer)) + { + a = ea_find(e->attrs->eattrs, EA_CODE(EAP_BGP, BA_MULTI_EXIT_DISC)); + if (a) + bgp_attach_attr(attrs, pool, BA_MULTI_EXIT_DISC, 0); + } } /* iBGP -> keep next_hop, eBGP multi-hop -> use source_addr, @@ -1317,9 +1323,11 @@ bgp_rte_better(rte *new, rte *old) } /* RFC 4271 9.1.2.2. d) Prefer external peers */ - if (new_bgp->is_internal > old_bgp->is_internal) + n = !!(new_bgp->is_internal || new_bgp->cf->iebgp_peer); + o = !!(old_bgp->is_internal || old_bgp->cf->iebgp_peer); + if (n > o) return 0; - if (new_bgp->is_internal < old_bgp->is_internal) + if (n < o) return 1; /* RFC 4271 9.1.2.2. e) Compare IGP metrics */ @@ -1424,7 +1432,9 @@ bgp_rte_mergable(rte *pri, rte *sec) } /* RFC 4271 9.1.2.2. d) Prefer external peers */ - if (pri_bgp->is_internal != sec_bgp->is_internal) + p = !!(pri_bgp->is_internal || pri_bgp->cf->iebgp_peer); + s = !!(sec_bgp->is_internal || sec_bgp->cf->iebgp_peer); + if (p != s) return 0; /* RFC 4271 9.1.2.2. e) Compare IGP metrics */ diff --git a/proto/bgp/bgp.h b/proto/bgp/bgp.h index e47a0eb1..8652fae8 100644 --- a/proto/bgp/bgp.h +++ b/proto/bgp/bgp.h @@ -51,6 +51,7 @@ struct bgp_config { int add_path; /* Use ADD-PATH extension [RFC7911] */ int allow_local_as; /* Allow that number of local ASNs in incoming AS_PATHs */ int allow_local_pref; /* Allow LOCAL_PREF in EBGP sessions */ + int iebgp_peer; /* Peer has different AS but should be treated as internal peer */ int gr_mode; /* Graceful restart mode (BGP_GR_*) */ int setkey; /* Set MD5 password to system SA/SP database */ unsigned gr_time; /* Graceful restart timeout */ diff --git a/proto/bgp/config.Y b/proto/bgp/config.Y index 55c602f1..f01a6fb6 100644 --- a/proto/bgp/config.Y +++ b/proto/bgp/config.Y @@ -27,7 +27,8 @@ CF_KEYWORDS(BGP, LOCAL, NEIGHBOR, AS, HOLD, TIME, CONNECT, RETRY, INTERPRET, COMMUNITIES, BGP_ORIGINATOR_ID, BGP_CLUSTER_LIST, IGP, TABLE, GATEWAY, DIRECT, RECURSIVE, MED, TTL, SECURITY, DETERMINISTIC, SECONDARY, ALLOW, BFD, ADD, PATHS, RX, TX, GRACEFUL, RESTART, AWARE, - CHECK, LINK, PORT, EXTENDED, MESSAGES, SETKEY, BGP_LARGE_COMMUNITY) + CHECK, LINK, PORT, EXTENDED, MESSAGES, SETKEY, BGP_LARGE_COMMUNITY, + IEBGP_PEER) CF_GRAMMAR @@ -129,6 +130,7 @@ bgp_proto: | bgp_proto ALLOW BGP_LOCAL_PREF bool ';' { BGP_CFG->allow_local_pref = $4; } | bgp_proto ALLOW LOCAL AS ';' { BGP_CFG->allow_local_as = -1; } | bgp_proto ALLOW LOCAL AS expr ';' { BGP_CFG->allow_local_as = $5; } + | bgp_proto IEBGP_PEER bool ';' { BGP_CFG->iebgp_peer = $3; } | bgp_proto GRACEFUL RESTART bool ';' { BGP_CFG->gr_mode = $4; } | bgp_proto GRACEFUL RESTART AWARE ';' { BGP_CFG->gr_mode = BGP_GR_AWARE; } | bgp_proto GRACEFUL RESTART TIME expr ';' { BGP_CFG->gr_time = $5; } -- 2.13.4

3 3

Bird v2, MPLS and LDP
by Maximilian Wilhelm 19 Sep '17

19 Sep '17

Hi folks, I've just seen in the NEWS for bird 2.0.0-pre1 that there are many MPLS related things coming. Kudos for that! Forgive me if this has been answered recently, I didn't find anything in my list archive: As of the available support for MPLS forwarding in the Linux kernel, I'm wondering if there is any rough roadmap the next releases? Are there any plans on integrating some LDP module (maybe also borrowing from the openldpd as FRR did? ;)) into bird? Thanks for your great work! Will someone of you folks at DENOG9? Best Max -- "Kunst ist Besessenheit. Du willst etwas unter Kontrolle bringen bevor es Dich kontrolliert." -- O

2 3

FreeBSD 11.1 OSPF multicast broken?
by Aragon Gouveia 19 Sep '17

19 Sep '17

Good day, There seems to be a multicast related bug with FreeBSD 11.1 and Bird 1.6.3. In summary: Two problems: * Ethernet interfaces configured as "broadcast" do not emit any OSPF packets, as observed by tcpdump. * Above interfaces receive OSPF packets from Linux neighbours (as seen by tcpdump), but Bird does not receive them (nothing logged in debug mode). Two workarounds: * Enabling "real broadcast" solves both problems above, but it must be enabled on all peers' configs so that everyone broadcasts. * Configuring interfaces as nbma on all peers also solves both problems. While Bird is running, there seem to be no OSPF multicast memberships reported by ifmcstat(8), eg. # ifmcstat -i vtnet1 -v vtnet1: inet 192.168.102.16 igmpv3 rv 2 qi 125 qri 10 uri 3 group 224.0.0.1 mode exclude mcast-macaddr 01:00:5e:00:00:01 link 52:54:00:85:d7:51 group 01:00:5e:00:00:01 I have also tried disabling firewalls, and have not seen any "Permission denied" socket errors logged by Bird in debug mode. I'd be delighted to help test/find a fix with my lab setup, but for now I'm a bit lost for digging into code and kernel APIs, which is where I suspect the problem lies. Any ideas where to start? Thanks, Aragon

3 9

BIRD export reject not working
by Marek Królikowski 19 Sep '17

19 Sep '17

Hello guys, I got strange problem with BGP i share data to Collector but i put to reject some bgp path.... This is how look configuration of BGP session of Collector: protocol bgp Collector { description "Collector"; local as MY-ASN; source address IPv61; neighbor IPV62 as SOMEONE-ASN; multihop; import none; export filter { if bgp_path.first = 64515 then reject; if bgp_path = 64515 then reject; if bgp_path.last = 64515 then reject; include "export.conf"; }; } But: root@pl-bgp:~# birdc6 show route export Collector all 2a0b:e206::/32 BIRD 1.6.3 ready. 2a0b:e206::/32 via 2a06:1287:330e:16::2 on bgp-fr [France 2017-09-18] * (100) [AS21430i] Type: BGP unicast univ BGP.origin: IGP BGP.as_path: MY-ASN 64515 20473 1299 21430 BGP.next_hop: 2a07:XXXX.XXXX.XXXX BGP.local_pref: 100 BGP.community: (64515,44) Like You see in BGP path there is 64515. How i export this to Collector if i put reject on export? What is wrong? I use BIRD 1.6.3. Best Regards Marek Krolikowski

4 4

Kernel dropped some netlink messages, will resync on next scan.
by Giuseppe Ravasio (LU) 13 Sep '17

13 Sep '17

Hi, I'm upgrading my core router (running an old bird 1.3.10) with a new Ubuntu 16.04 running 1.6.3 from the official PPA. Actually it'a a pretty simple configuration ISP3 ISP1 ISP2 | | | | | | NEWROUTER=====<iBGP>======OLDROUTER | | ipv4/21 ipv6/32 In the new router i find a lot of messages "Kernel dropped some netlink messages, will resync on next scan." for both IPv6 and IPv4 For IPv6 daemon this seems to happen only when i start the sessions and load the full table and so I think it could be acceptable. For IPv4 daemon this seems to happen *a lot* when I start the BGP session with the iBGP enabled (and also this I think could be acceptable), but the message gets printed sometimes (a single line every 5/10 minutes) when the BGP is running normally. I already tried to adjust the net.core mem kernel parameters with: net.core.rmem_max = 8388608 net.core.wmem_max = 8388608 net.core.optmem_max = 65536 net.core.rmem_default=1064960 net.core.wmem_default=1064960 But the messages are still there. Any hints? maybe the rmem_default is still too low? Thanks Giuseppe

3 6

documentation on emptying bgp_community
by Alexander Zubkov 13 Sep '17

13 Sep '17

Hello. I have found a couple of methods to make bgp_community empty: 1) bgp_community.empty 2) bgp_community = -empty- But neither of them are present in the documentation. Only example in bird.conf.example file. I think it will be good to have this documented.

2 1

reload configuration without changing protocol state
by Alexander Zubkov 12 Sep '17

12 Sep '17

Hello. I want to be able to reload bird's configuration so it will not change current protocol's state. For example if I run bird with some protocols and then disable one of them from the console and at finally I run "configure" of "configure soft" to reload a configuration (new filters for example) - I get that protocol restarted too: bird> show protocols name proto table state since info device1 Device master up 2017-09-09 static1 Static master up 18:07:29 bird> disable static1 static1: disabled bird> show protocols name proto table state since info device1 Device master up 2017-09-09 static1 Static master down 18:10:01 bird> configure soft Reading configuration from /etc/bird.conf Reconfigured bird> show protocols name proto table state since info device1 Device master up 2017-09-09 static1 Static master up 18:10:10 bird> But I want protocol to still be disabled in this case. Because I have disabled it manually and want it to be started manually. Is there a way of reloading configuration, keeping manual state of protocols? I have already tried documentation and Google, but with no luck. >

1 0

Re: BIRD IP tunnel problem
by Ondrej Zajicek 12 Sep '17

12 Sep '17

Hi BIRD does not handle well situations where there are overlapping IP ranges on interfaces. It just find a first iface that matches the next-hop. It is true that one would expect that in 'direct' mode, the iface is used also for the next hop, but even in that case BGP is two-level and BGP next hop is resolved through iface prefixes to find the next hop iface. You could try attached patch that will change the behavior that in 'direct' mode always use the iface over which the BGP session is configured. -- 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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