March 2019 - Bird-users - Mailing Lists

Import filter on 2nd ASN in AS path?
by Robert Scheck 29 Mar '19

29 Mar '19

Hello folks, can I somehow import filter only on the 2nd AS number in the AS path? I know with the snippet below (heavily inspired by bgpfilterguide.nlnog.net) I can filter on AS numbers that appear somewhere in the AS path, however this import filter catches by nature also some pseudo-legitimate networks. define BOGON_ASNS = [ 0, 23456, 64496..64511, 64512..65534, 65535, 65536..65551, 65552..131071, 4200000000..4294967294, 4294967295 ]; if (bgp_path ~ BOGON_ASNS) then { print "Detected bogon AS path: ", net, " ", bgp_path, ", (neighbour ", from, ")"; } There are unfortunately some transits with broken export filters which e.g. export their DSL/FTTC and FTTH networks using private ASNs and I would like to explicitly filter these (example path: AS-TRANSIT AS-BOGON1 AS-BOGON2). The documentation has hints for first and last ASN in path, but this would catch in above example only AS-TRANSIT or AS-BOGON2, but not AS-BOGON1. Any pointers? Thank you. Regards, Robert

4 5

bird 2.0.4 autodetects /30 as ptp
by Kenth Eriksson 28 Mar '19

28 Mar '19

It seems as bird autodetects a /30 OSPF interface as ptp. bird> show ospf interface ospfv2_1: Interface eth0 (10.210.138.32/30) Type: ptp Area: 0.0.0.0 (0) State: PtP Priority: 0 Cost: 10 Hello timer: 10 Wait timer: 40 Dead timer: 40 Retransmit timer: 5 bird> Is this really correct behaviour? The peering Cisco router thinks the /30 network is a broadcast interface... Thanks, Kenth

3 5

BGP end mark
by Arvin Gan 26 Mar '19

26 Mar '19

Hi Ondrej, In bgp_create_end_mark(), suggest to add condition ext_next_hop to select ip_end_mark or mp_end_mark that is aligned with bgp_create_update function, although this don't affect protocols communication :) @@ -2225,7 +2297,7 @@ bgp_create_end_mark(struct bgp_channel * BGP_TRACE(D_PACKETS, "Sending END-OF-RIB"); - return (c->afi == BGP_AF_IPV4) ? + return (c->afi == BGP_AF_IPV4) && !c->ext_next_hop ? bgp_create_ip_end_mark(c, buf): bgp_create_mp_end_mark(c, buf); } Best Regards, Arvin Gan

1 0

BGP import_table & graceful restart issue
by Arvin Gan 25 Mar '19

25 Mar '19

Hi All, I am using BIRD 2.0.4, the configuration of bgp.ipv4 for import table and graceful restart are yes . when BGP remote peer is restarting, the graceful restart is detected by the local peer, using "show route protocols bgp1" on local peer, the route related with the restarting peer are exist, I think it's correct. But when I using "show route import table bgp1.ipv4" to show route for local peer Adj-RIB-In , the route is empty, correct ? After the remote peer is restarted done, the local import table can be recovered. As RFC4274 description: "when the Receiving Speaker detects termination of the TCP session for a BGP session with a peer that has advertised the Graceful Restart Capability, it MUST retain the routes received from the peer for all the address families that were previously received in the Graceful Restart Capability and MUST mark them as stale routing information." Best Regards, Arvin Gan

2 3

How to ignore OSPF MTU checking?
by Kenth Eriksson 25 Mar '19

25 Mar '19

Is there a way to disable OSPF MTU checking? In Cisco the relevant command is 'ip ospf mtu-ignore'. Thanks, Kenth

3 5

OSPF authentication problem between Cisco and Bird
by Jérémie Vandeville 24 Mar '19

24 Mar '19

Hi everyone I apologise in advance, english is not my native language... For study purpose, I'm trying to setup OSPFv2 between Bird 1.6.6 and a Cisco router. It seems there is a problem with the auth-type code send by Bird in the ospf hello packets. This problem prevent the devices to become neighbours. Here is the configuration of the Cisco router : router ospf 1 no capability lls network 192.168.42.0 0.0.0.255 area 0.0.0.0 interface Vlan10 description Management ip address dhcp ip ospf authentication ip ospf authentication-key azerty ip ospf dead-interval 6 ip ospf hello-interval 2 And the configuration of Bird : router id 1.1.1.1; protocol device { } protocol kernel { metric 64; import all; export all; } protocol ospf test { instance id 42; area 0.0.0.0 { interface "eth*" { hello 2; dead count 3; authentication simple; password "azerty"; }; }; export all; } If I launch the debug command on the Cisco, I see this : Mar 23 18:09:59: OSPF-1 PAK : Vl10: OUT: 192.168.42.43->224.0.0.5: ver:2 type:1 len:44 rid:192.168.42.43 area:0.0.0.0 chksum:2720 auth:1 Mar 23 18:09:59: OSPF-1 PAK : Vl10: IN: 192.168.42.73->224.0.0.5: ver:2 type:1 len:52 rid:1.1.1.1 area:0.0.0.0 chksum:F0CE auth:10753 Bird send the field auth-type with the value 10753. Tcpdump show the same value : 17:13:38.012494 IP (tos 0xc0, ttl 1, id 21850, offset 0, flags [none], proto OSPF (89), length 64) 192.168.42.43 > 224.0.0.5: OSPFv2, Hello, length 44 Router-ID 192.168.42.43, Backbone Area, Authentication Type: simple (1) Simple text password: azerty 17:13:38.012792 IP (tos 0xc0, ttl 1, id 7301, offset 0, flags [none], proto OSPF (89), length 72) 192.168.42.73 > 224.0.0.5: OSPFv2, Hello, length 52 Router-ID 1.1.1.1, Backbone Area, Authentication Type: unknown (10753) Can you tell me what I'm doing wrong ? If I try the "none" authentication, Bird send the code 10752 and the problem is the same... Thx !

2 1

LSA type-3
by Ticlea Alexandru 22 Mar '19

22 Mar '19

Hello Is a way to control what subnets are sent by ABR to another area in LSA type3? I can use "hidden" to declare what subnets must not be propagated, but I want to do it in oppositeside. Area 0.0.0.10 contains subnets in A.B.0.0/16 and I want to prevent the propagation of others, like A.C.D.0/24. Is a way other than listing many subnets (/8 and /16) as hidden?

2 1

Feature request - syslog equivalent for filter language
by remco van mook 22 Mar '19

22 Mar '19

Hi, would it be possible to add a function to Bird that’s essentially the same as syslog in C? That way we can have filters/function log messages including severity which is very helpful for debugging and monitoring. I tried to implement this in the bird configuration language itself, but got stuck on either of two points: - Bird can’t concatenate strings - function definitions need to have a predefined number of arguments Ideally I’d like to replace a statement like print "REJECTING: ",net.ip,"/",net.len," received from ",from," AS ",bgp_path.first,": Prefix is a martian"; with syslog LOG_WARNING, "REJECTING: ",net.ip,"/",net.len," received from ",from," AS ",bgp_path.first,": Prefix is a martian”; Right now I’m just commenting out the print statements that get hit too often to prevent spamming log files with ten thousands of rows, and ideally I’d like to use the log command that Bird uses for it’s own messages to set where these messages should go based on relevance. thanks Remco

2 3

BGP Monitoring protocol support
by knet solutions 22 Mar '19

22 Mar '19

Hi, Does bird support BMP? https://tools.ietf.org/html/rfc7854 Thanks suresh -- *Regards, * *Knet solutions.* Whatsapp/Mobile: +919445042007 website: http://knetsolutions.in/ Facebook Page : https://www.facebook.com/sdntraining/ youtube channel: https://www.youtube.com/channel/UCTD6X9_oDqIYs_xpE7moFnQ

2 1

BIRD 2.0 BGP AS Path Prepending
by L Ken 21 Mar '19

21 Mar '19

Hi, As mentioned in https://bird.network.cz/pipermail/bird-users/2017-December/011774.html, BIRD 2.0 calls export_filter before LOCAL-AS is set to bgp_path. In BIRD 1.6, following export filter create AS path "10001 10002 10003": protocol bgp bgp1 { # some required bgp config here local as 10003; export filter { bgp_path.prepend(10002); bgp_path.prepend(10001); } } The same filter in BIRD 2.0 create AS path "10003 10001 10002" : protocol bgp bgp1 { # some required bgp config here local as 10003; ipv4 { export filter { bgp_path.prepend(10002); bgp_path.prepend(10001); } } } Is there any way to "prepend" AS to Local-AS in BIRD 2.0 with result same as 1.6? Thanks, --- K

3 2