July 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

4 5

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

3 5

[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

3 4

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

3 3

For developer, required some explanation on code with timer and BGP
by Mattia Milani 06 Apr '19

06 Apr '19

Hello all, this is a message for developer and who know how bird use timer, and buffer. Sorry for the length of this mail. For first, the protocol i want to modify and upgrade is BGP, i see that there isn't the timer MRAI implemented and it will be useful for some studies on information propagation, so i decided to develop a first version of it. The actual process to send any kind of pkt is to call the function bgp_fire_tx() and it's called by two other function respectively bgp_kick_tx() and bgp_tx() and the function bgp_fire_tx() take care to read from the buffer the message that has to be sent and send it. bgp_kick_tx() and bgp_tx() call bgp_fire_tx() while it don't return 0, so the clear all the buffer of the message that has to be sent. So my idea to introduce MRAI was that: Create a timer (for now I created it for connection, after like say RFC 4271 this timer has to be set for every route) and put it on the connection. Initialize it with the other timer of the conn when the state of the conn goes up i set it to some value and start the timer. when the timer finish i call the function MRAI_finish() that call the function bgp_fire_tx() while there is something to send more ore less like the while loop in bgp_kick_tx() and bgp_tx() when it's called bgp_fire_tx() on the update message part i written a check, if the timer isn't at 0 i can't send the update, because the function can be called from bgp_kick_tx() or bgp_tx(), but if it 0 it is finished so i can send the message When all the message had been send i reset the timer and start it again. But unfortunately i see something that doesn't make my code work. when something call bgp_kick_tx() or bgp_tx() the call bgp_fire_tx() and they clear all the buffer, including update message that wasn't sended so when the timer finish it didn't found anything on the buffer. Now how can i change that? My idea is to use a secondary buffer, when in bgp_fire_tx() i see that i can't send the update I will insert the pkt in this secondary buffer and consume the pkt on the main buffer. when bgp_kick_tx() or bgp_tx() have send all the messages I will transfer all the pkt in the secondary buffer into the main buffer. So I ask you it's possible that? there is something in the code already written that could help me? do you see another way to implement the MRAI timer? Thanks a lot to everyone, Mattia

2 3

Opaque pipe in bird 2.0?
by Piotr Wydrych 21 Aug '18

21 Aug '18

Hi, Having a table with 2 paths per prefix, I need to send only the best path to another table, like this: +------+ +------+ |table1| |table2| +------+ +------+ \ / \ / +v-v+ |all| +-+-+ | | +----v----+ |best_only| +---------+ As far as I remember, I could use pipe with opaque mode to achieve that in Bird 1.6. After mode has been removed in Bird 2.0, is there any simple way to do it by using pipe and filters? Currently, I configured to have a BGP session to itself to send the best paths, but I consider it as a dirty workaround... BTW, documentation for pipe in 2.0 still mentions the opaque mode - http://bird.network.cz/?get_doc&v=20&f=bird-6.html#ss6.8 (2nd and 3rd paragraph). Best, Piotr -- Piotr 'GhosT' Wydrych ...... Senior II Lead Sw. Eng., SDN ....... Akamai ........................................................................ A: Because it messes up the order in which people normally read text. .. Q: Why is top-posting such a bad thing? ................................

3 3

[PATCH RFC 0/2] Adding HMAC support to the Babel protocol
by Toke Høiland-Jørgensen 15 Aug '18

15 Aug '18

The Babel IETF working group is in the process of specifying an extension to the Babel protocol that adds HMAC authentication of messages. The current draft proposal is available as draft-do-babel-hmac-00: https://tools.ietf.org/html/draft-do-babel-hmac-00 This patch adds an implementation of this draft to Babel in Bird. The draft is a way from being finalised, so it is premature to merge the code. Instead, this should be seen as a call for feedback on both the implementation and the draft specification. The proof of concept implementation of HMAC for babeld is available in the hmac-challenge branch of this repository: https://github.com/wkolod/babeld With this patch, Bird can successfully exchange HMAC-authenticated messages with babeld in the above repo. -Toke --- Toke Høiland-Jørgensen (2): babel: Define helper macro for looping through TLVs babel: Add HMAC support proto/babel/babel.c | 80 +++++++++ proto/babel/babel.h | 58 ++++++ proto/babel/config.Y | 34 ++++ proto/babel/packets.c | 439 +++++++++++++++++++++++++++++++++++++++++++++---- 4 files changed, 567 insertions(+), 44 deletions(-)

3 14

BIRD not redistributing iBGP routes
by Matthias Merkel 31 Jul '18

31 Jul '18

I have three BIRD routers: A uses iBGP only B also only uses iBGP C uses eBGP and iBGP They are connected as follows: A<->B<->C (all via iBGP) The goal is to allow A to announce routes to B, have B redistribute the route to C and have C announce it to the peers. The issue is that B receives the route (and adds it to the kernel) however it does not send it to C. Any ideas how to fix this? Matthias Merkel CTO BoltN Hosting Limited c-Level Phone +498941207255 Mobile +4915752259219 Email matthias(a)boltn-hosting.com Skype matthias_merkel1 Follow us <https://img.beta.newoldstamp.com/r/27887/twitter> <https://img.beta.newoldstamp.com/r/27887/linkedin> <https://img.beta.newoldstamp.com/r/27887/android> <https://img.beta.newoldstamp.com/r/27887/whatsapp>

3 2

lists issue
by Arvin Gan 27 Jul '18

27 Jul '18

Hi all, There may be an issue in blow function when deleted the node is the first one, that mean n->prev is NULL....., similarly, same issue as the last one node is deleted. LIST_INLINE void rem_node(node *n) { node *z = n->prev; node *x = n->next; z->next = x; x->prev = z; n->next = NULL; n->prev = NULL; } Thanks Arvin

2 1

Not getting out of "Connect" state
by Scott Ellentuch 26 Jul '18

26 Jul '18

Hi, I've had a bird(1.4.5)<>bird(1.5.0) up and running for 2 months now, and I was forced to reboot one of the servers. Now I can't get them to re-establish.... bgp_aws1 BGP master start 12:15:07 Connect bgp_isp1 BGP master start 12:14:08 Connect I've disable them both, waited a bit, then enabled them both with no luck. Tried a few times. Is there somewhere/something else I should be checking? I know BGP should be BGP, but is it potentially a glitch between 2 versions (I have another set just like this, and disable/wait/enable resolved that) Tnx, Tuc

2 1