February 2017 - Bird-users

Adding a grammar rule with conditional compilation
by Dean 28 Feb '17

28 Feb '17

Hello, I'm modifying some parts of the code, and I've added a new grammar rule for creating static routes in the config.Y file. However, I would like this rule to only be enabled based on a preprocessor definition, with an #ifdef, or throw a syntax error otherwise. I can't figure out a way to do this? Any suggestions? Thank you.

2 1

Will bird block on syslog() call?
by Pavlos Parissis 28 Feb '17

28 Feb '17

Hi, We have observed some instability on BFD protocol, where upstream router and/or the server (Linux RedHat 7.3) declares the BFD session dead and as consequence upstream router stops forwarding traffic to the server (we utilize ECMP). Our current hypothesis is that Bird log messages (only BGP KEEPALIVE messages when there isn't any route change) via syslog glibc function, which connects to UNIX socket (/dev/log) and the sender (Bird daemon) may block when the receiver (rsyslogd) doesn't response fast enough or the buffer is full. On RedHat 7 servers there is a chain of daemons, which receive log messages via UNIX socket. systemd-journald.service listens on /dev/log UNIX SOCKET and forwards messages to /run/systemd/journal/syslog UNIX SOCKET where rsyslogd listens on. As far as I can see in the code and in the output of ps -eLl, Bird daemon is a single threaded process (please correct me if I am wrong), so it could be that a call to syslog blocks for X seconds when X is higher than the failure detection time. Can you confirm this hypothesis? Here is an sanitized config: log syslog { debug, trace, info, remote, warning, error, auth, fatal, bug }; /* Source configuration snippets Please make sure they are valid snippets for Bird */ include "/etc/bird.d/*.conf"; include "/etc/bird.d/4/*.conf"; router id 1.2.3.1; protocol device { scan time 10; } protocol static { disabled yes; } protocol direct direct1 { interface "lo"; debug all; export none; import where net ~ ANYCAST_NETWORKS; } protocol bfd BFD1 { debug { states, routes, filters, interfaces, events }; interface "north", "south" { min rx interval 400 ms; min tx interval 400 ms; idle tx interval 1000 ms; multiplier 3; }; } protocol bgp BGP1 { disabled no; description "Peer-BGP1"; neighbor 1.2.3.254 as 4; source address 1.2.3.1; bfd on; debug all; import none; export where match_route_north(); direct; hold time 10; startup hold time 240; connect retry time 120; keepalive time 3; start delay time 5; error wait time 60, 300; error forget time 300; disable after error off; next hop self; path metric 1; default bgp_med 0; default bgp_local_pref 0; local as 1; } protocol bgp BGP2 { disabled no; description "Peer-BGP2"; neighbor 1.2.4.254 as 7; source address 1.2.3.1; bfd on; debug all; import none; export where match_route_south(); direct; hold time 10; startup hold time 240; connect retry time 120; keepalive time 3; start delay time 5; error wait time 60, 300; error forget time 300; disable after error off; next hop self; path metric 1; default bgp_med 0; default bgp_local_pref 0; local as 1; } Cheers, Pavlos

2 3

how to change OSPF route src ?
by Илья Шипицин 27 Feb '17

27 Feb '17

Hello, I run bird on centos with multiple ip addresses. what I want to achive might be easily done by running command ip route change default via $def src N.N.N.N where $def is variable and N.N.N.N is local address how can I achive that with bird ? any ospf route magic ? scripting after bird applies routes (I need to pick $def from that script) thanks! Ilya Shipitsin

2 1

filters, line 1360: ~ applied on unknown type pair
by Борис Коваленко 27 Feb '17

27 Feb '17

Hello! AFAIK, this is line 1360 of your config. Regards, Boris -- С уважением, Борис Коваленко

2 2

Version 2.0.0pre0
by Ondrej Filip 23 Feb '17

23 Feb '17

Dear BIRD users, it took us a very long time, but we are moving towards 2.0.x branch. Main feature of this branch is IPv4 and IPv6 integration. Please note, 2.0.x will be an _experimental_ branch. We will not guarantee configuration stability etc. And today we release 2.0.0-pre0. So that's experimental version of experimental branch. Keep this in mind and DO NOT USE IT IN PRODUCTION ENVIRONMENT. On the other hand, testers are more than welcome. Please use it and report (either positive or negative)! We will not provide packages for any distribution. Version 2.0.0-pre0 (2016-12-07) o Integrated IPv4 + IPv6 design o Major BGP protocol redesign o BGP multicast support (SAFI 2) o BGP flowspec support (RFC 5575) o New RPKI-Router protocol o New build system o Unit tests Notes: Protocols and tables are now connected using explicit channels, most related protocol options (table, import, export, ...) are now channel options. See doc/bird.conf.example2 for configuration examples. Ondrej

8 11

[PATCH,RFC] Allow exchanging LOCAL_PREF with eBGP peers.
by Lennert Buytenhek 23 Feb '17

23 Feb '17

Hello! I've attached a patch that allows (selectively) exchanging LOCAL_PREF with eBGP peers. The BGP RFC (RFC4271) says that you shouldn't send LOCAL_PREF to eBGP peers, but most modern BGP implementations have an override to allow doing this anyway, and it is very useful in some scenarios, for example if you have a network topology a la RFC7938. This patch enables this functionality by the 'ebgp localpref' clause in a bgp protocol statement, for example: protocol bgp mypeer { [...]; ebgp localpref rx; } This option works like 'add paths', in that the possible arguments are "rx" or "tx" or a bool (where "yes" means both rx and tx). RFC4271 also specifies that if LOCAL_PREF is received from an eBGP speaker, it should be ignored (and you should not reply with a NOTIFICATION), so it should be safe to send LOCAL_PREF to eBGP peers that are not expecting it, and it's safe to send it to another bird -- but there are various reasons why you might not want to do that, of course. I'm not submitting this patch for inclusion yet at this point (which is why there is no documentation), but this kind of functionality is useful for us, and I'd like to hear from people whether they think this could be useful for them, too. And of course, there will have to be a lot of bikeshedding about the name of the config option! :-) Cheers, Lennert Signed-off-by: Lennert Buytenhek <lbuytenhek(a)fastly.com> diff --git a/proto/bgp/attrs.c b/proto/bgp/attrs.c index 9d23374..3730021 100644 --- a/proto/bgp/attrs.c +++ b/proto/bgp/attrs.c @@ -307,7 +307,7 @@ static struct attr_desc bgp_attr_table[] = { bgp_check_next_hop, bgp_format_next_hop }, { "med", 4, BAF_OPTIONAL, EAF_TYPE_INT, 1, /* BA_MULTI_EXIT_DISC */ NULL, NULL }, - { "local_pref", 4, BAF_TRANSITIVE, EAF_TYPE_INT, 0, /* BA_LOCAL_PREF */ + { "local_pref", 4, BAF_TRANSITIVE, EAF_TYPE_INT, 1, /* BA_LOCAL_PREF */ NULL, NULL }, { "atomic_aggr", 0, BAF_TRANSITIVE, EAF_TYPE_OPAQUE, 1, /* BA_ATOMIC_AGGR */ NULL, NULL }, @@ -822,8 +822,13 @@ bgp_get_bucket(struct bgp_proto *p, net *n, ea_list *attrs, int originate) code = EA_ID(a->id); if (ATTR_KNOWN(code)) { - if (!bgp_attr_table[code].allow_in_ebgp && !p->is_internal) - continue; + if (!p->is_internal) + { + if (!bgp_attr_table[code].allow_in_ebgp) + continue; + if (code == BA_LOCAL_PREF && !(p->cf->ebgp_local_pref & EBGP_LOCAL_PREF_TX)) + continue; + } /* The flags might have been zero if the attr was added by filters */ a->flags = (a->flags & BAF_PARTIAL) | bgp_attr_table[code].expected_flags; if (code < 32) @@ -1777,8 +1782,13 @@ bgp_decode_attrs(struct bgp_conn *conn, byte *attr, uint len, struct linpool *po { errcode = 5; goto err; } if ((desc->expected_flags ^ flags) & (BAF_OPTIONAL | BAF_TRANSITIVE)) { errcode = 4; goto err; } - if (!desc->allow_in_ebgp && !bgp->is_internal) - continue; + if (!bgp->is_internal) + { + if (!desc->allow_in_ebgp) + continue; + if (code == BA_LOCAL_PREF && !(bgp->cf->ebgp_local_pref & EBGP_LOCAL_PREF_RX)) + continue; + } if (desc->validate) { errcode = desc->validate(bgp, z, l); diff --git a/proto/bgp/bgp.c b/proto/bgp/bgp.c index 0f1c944..fae4be5 100644 --- a/proto/bgp/bgp.c +++ b/proto/bgp/bgp.c @@ -1556,7 +1556,7 @@ bgp_show_proto_info(struct proto *P) (c->peer_add_path & ADD_PATH_RX) ? " add-path-rx" : "", (c->peer_add_path & ADD_PATH_TX) ? " add-path-tx" : "", c->peer_ext_messages_support ? " ext-messages" : ""); - cli_msg(-1006, " Session: %s%s%s%s%s%s%s%s", + cli_msg(-1006, " Session: %s%s%s%s%s%s%s%s%s%s", p->is_internal ? "internal" : "external", p->cf->multihop ? " multihop" : "", p->rr_client ? " route-reflector" : "", @@ -1564,7 +1564,9 @@ bgp_show_proto_info(struct proto *P) p->as4_session ? " AS4" : "", p->add_path_rx ? " add-path-rx" : "", p->add_path_tx ? " add-path-tx" : "", - p->ext_messages ? " ext-messages" : ""); + p->ext_messages ? " ext-messages" : "", + (p->cf->ebgp_local_pref & EBGP_LOCAL_PREF_RX) ? " ebgp-localpref-rx" : "", + (p->cf->ebgp_local_pref & EBGP_LOCAL_PREF_TX) ? " ebgp-localpref-tx" : ""); cli_msg(-1006, " Source address: %I", p->source_addr); if (P->cf->in_limit) cli_msg(-1006, " Route limit: %d/%d", diff --git a/proto/bgp/bgp.h b/proto/bgp/bgp.h index d028bef..6e68d35 100644 --- a/proto/bgp/bgp.h +++ b/proto/bgp/bgp.h @@ -49,6 +49,7 @@ struct bgp_config { int interpret_communities; /* Hardwired handling of well-known communities */ int secondary; /* Accept also non-best routes (i.e. RA_ACCEPTED) */ int add_path; /* Use ADD-PATH extension [draft] */ + int ebgp_local_pref; /* Exchange LOCAL_PREF with eBGP peers */ int allow_local_as; /* Allow that number of local ASNs in incoming AS_PATHs */ int gr_mode; /* Graceful restart mode (BGP_GR_*) */ int setkey; /* Set MD5 password to system SA/SP database */ @@ -79,6 +80,9 @@ struct bgp_config { #define ADD_PATH_TX 2 #define ADD_PATH_FULL 3 +#define EBGP_LOCAL_PREF_RX 1 +#define EBGP_LOCAL_PREF_TX 2 + #define BGP_GR_ABLE 1 #define BGP_GR_AWARE 2 diff --git a/proto/bgp/config.Y b/proto/bgp/config.Y index 32ae88a..5db122d 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, + EBGP, LOCALPREF) CF_GRAMMAR @@ -126,6 +127,9 @@ bgp_proto: | bgp_proto ADD PATHS RX ';' { BGP_CFG->add_path = ADD_PATH_RX; } | bgp_proto ADD PATHS TX ';' { BGP_CFG->add_path = ADD_PATH_TX; } | bgp_proto ADD PATHS bool ';' { BGP_CFG->add_path = $4 ? ADD_PATH_FULL : 0; } + | bgp_proto EBGP LOCALPREF RX ';' { BGP_CFG->ebgp_local_pref = EBGP_LOCAL_PREF_RX; } + | bgp_proto EBGP LOCALPREF TX ';' { BGP_CFG->ebgp_local_pref = EBGP_LOCAL_PREF_TX; } + | bgp_proto EBGP LOCALPREF bool ';' { BGP_CFG->ebgp_local_pref = $4 ? (EBGP_LOCAL_PREF_RX | EBGP_LOCAL_PREF_TX) : 0; } | 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 GRACEFUL RESTART bool ';' { BGP_CFG->gr_mode = $4; }

5 12

Fwd: Bird / OpenBSD / BGP MD5 authentication walkthrough
by Darren Marshall 23 Feb '17

23 Feb '17

I'm googling like crazy and can't seem to find an example of how to configure MD5 authentication between BGP peers using Bird running on OpenBSD, does someone out there have a guide for this? The Bird config is straightforward but I'm missing the 'glue' at the OS level! Also does anyone know if the stock Generic kernel supports TCP MD5 signatures out of the box (OpenBSD 6.0) , looking at the kernel config file it would appear it has the option compiled in , anyone know how to check?. Many thanks in advance! daz

2 5

kernel dropped netlink messages
by Erwin Lubbers 23 Feb '17

23 Feb '17

Hi, Since we upgraded our Bird installation to 1.6.3 (from 1.6.0), we do get some "bird: Kernel dropped some netlink messages, will resync on next scan." messages in our syslogs. What does this message mean and how can we prevent it? Regards, Erwin

1 0

Re: Bird / OpenBSD / BGP MD5 authentication walkthrough
by Darren Marshall 21 Feb '17

21 Feb '17

Thanks Pawel, Yeah I have this working on FreeBSD and Quagga but Bird / OpenBSD I am struggling with :( . Anyone out there got a working example of the steps required from MD5 authentication for BGP neighbours using Bird on OpenBSD?. Thanks daz On 21 February 2017 at 17:43, Paweł Nastachowski < Pawel.Nastachowski(a)eu.equinix.com> wrote: > Hi, > > sorry my fault, I use setkey on freebsd. Maybe You can try > http://man.openbsd.org/ipsec.conf.5 > > Wiadomość napisana przez Darren Marshall <darren(a)tuff.org.uk> w dniu > 21.02.2017, o godz. 18:35: > > Hi Pawel, > > Thanks for this , much appreciated , do you know what package set key is > part of , I don't have it on my system at the moment! > > Cheers daz > > On 21 February 2017 at 17:00, Paweł Nastachowski <Pawel.Nastachowski@eu. > equinix.com> wrote: > >> >> Wiadomość napisana przez Darren Marshall <darren(a)tuff.org.uk> w dniu >> 21.02.2017, o godz. 17:01: >> >> >> I'm googling like crazy and can't seem to find an example of how to >> configure MD5 authentication between BGP peers using Bird running on >> OpenBSD, does someone out there have a guide for this? The Bird config is >> straightforward but I'm missing the 'glue' at the OS level! Also does >> anyone know if the stock Generic kernel supports TCP MD5 signatures out of >> the box (OpenBSD 6.0) , looking at the kernel config file it would appear >> it has the option compiled in , anyone know how to check?. >> >> You can use setkey. For example: >> >> cat bgp-md5.conf >> flush; >> add 195.182.218.100 195.182.218.39 tcp 0x1000 -A tcp-md5 „password” >> >> and >> >> setkey -f bgp-mf5.conf >> >> >> — >> Paweł Nastachowski >> Technical Manager >> >> EQUINIX | Al. Jerozolimskie 65/79 Warsaw 00-697 Warszawa, Poland >> E pawel.nastachowski(a)eu.equinix.com | T +48 22 427 39 98 | M +48 667 383 >> 108 <+48%20667%20383%20108> >> >> HOW ARE WE DOING? <http://www.customersat3.com/csc/equinix> Please >> click here to Tell Equinix - We're Listening >> >> Equinix.com <http://www.equinix.com/> | Twitter >> <https://twitter.com/equinix> | LinkedIn >> <http://www.linkedin.com/company/equinix> | Facebook >> <http://www.facebook.com/Equinix> | YouTube >> <http://www.youtube.com/user/equinixvideos> >> Equinix (Poland) Sp. z o.o. jest wpisana do Rejestru Przedsiębiorców >> Krajowego Rejestru Sądowego prowadzonego przez Sąd Rejonowy dla m. st. >> Warszawy w Warszawie, XII Wydział Gospodarczy, pod numerem KRS 0000295130, >> NIP 7010109699, REGON 141274596. Kapitał zakładowy spółki wynosi 530.000zł. >> Equinix (Poland) Sp. z o.o. is entered into the National Court Register >> maintained by the District Court for the Capital City of Warsaw, XII >> Economic Department in Warsaw, under KRS number 0000295130, VAT-ID >> PL7010109699, REGON 141274596.The share capital is PLN 530,000 >> >> >> >> >> > > — > Paweł Nastachowski > Technical Manager > > EQUINIX | Al. Jerozolimskie 65/79 Warsaw 00-697 Warszawa, Poland > E pawel.nastachowski(a)eu.equinix.com | T +48 22 427 39 98 | M +48 667 383 > 108 <+48%20667%20383%20108> > > HOW ARE WE DOING? <http://www.customersat3.com/csc/equinix> Please click > here to Tell Equinix - We're Listening > > Equinix.com <http://www.equinix.com/> | Twitter > <https://twitter.com/equinix> | LinkedIn > <http://www.linkedin.com/company/equinix> | Facebook > <http://www.facebook.com/Equinix> | YouTube > <http://www.youtube.com/user/equinixvideos> > Equinix (Poland) Sp. z o.o. jest wpisana do Rejestru Przedsiębiorców > Krajowego Rejestru Sądowego prowadzonego przez Sąd Rejonowy dla m. st. > Warszawy w Warszawie, XII Wydział Gospodarczy, pod numerem KRS 0000295130, > NIP 7010109699, REGON 141274596. Kapitał zakładowy spółki wynosi 530.000zł. > Equinix (Poland) Sp. z o.o. is entered into the National Court Register > maintained by the District Court for the Capital City of Warsaw, XII > Economic Department in Warsaw, under KRS number 0000295130, VAT-ID > PL7010109699, REGON 141274596.The share capital is PLN 530,000 > > > > >

1 0

FreeBSD ECMP Bird OSPF
by Cassiano Peixoto 21 Feb '17

21 Feb '17

Hi guys, Anyone knows if Bird OSPF supports FreeBSD ECMP (RADIX_MPATH kernel option)? I heard there is no compatibility. Please anyone who is running ou had success can confirm? Thanks.

4 5