August 2013 - Bird-users

IS-IS
by kveri new 01 Jun '15

01 Jun '15

Hello, I would like to implement IS-IS as a part of my master thesis. Are there any apparent problems which would prevent successful implementation, political and/or technical? Also I would like to hear opinions of the authors. Implementation timeframe is 2013 (if we live past 21th). Regards, Martin Čechvala Faculty of Informatics and Information Technologies Slovak Technical University

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OSFP LSA_MAXSEQNO problems
by Alexander V. Chernikov 23 Feb '14

23 Feb '14

Hello list! Currently bird performs LSA premature aging in very strange way which sometimes upsets quagga (up to SIGSEGV) and Cisco. Every time aging is done via setting seq number to LSA_MAXSEQNO. RFC 2328, on the opposite, shows us only 2 cases where MaxSequenceNumber is used in outgoing LSAs: 1) Self LSA originating with given seq num (very rare event) 2) [Premature] Aging of LSA from 1) because a) disappeared net and b) seq number increase (12.1.6) For all other cases seq number should be either increased or left intact. Bird, however, insist on setting LSA_MAXSEQNO while: 1) Receiving self-originating LSA which is not in local LSDB ( ospf_lsupd_receive ) which is not a special case according to 14.1 2) In all other places like handling if-down, external route disappear, etc... ( ospf_lsupd_flush_nlsa ) IT takes noticeable time (sometimes up to 5 seconds) for Cisco 65XX with ~40 neighbors to age given LSA (however it seems that problem is repeatable for ASR9k, too). And while such LSA is in database, every new update is ignored due to 13 step (8). (I've got full logs and pcap for given situation). Can we please consider applying attached patch to make it more compliant?

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filters: strange protocol restarts
by Sergey Popovich 03 Oct '13

03 Oct '13

Hello community!! And again I need to spread some light on BIRD behavior: why bird restarts protocol instead of just reloading it when no filter changes in configuration when using prefix set constant? There is simple configuration and steps to reproduce this ------------------------------------------------------------------------- # Configure logging log syslog all; log stderr all; router id 172.16.1.1; protocol device devices { scan time 15; } ### KRT 10 table rt_10; # This function does not forces "kernel" protocol to reload. function f1(prefix pfx) { if pfx ~ [ 192.168.0.0/16+ ] then return false; return true; } protocol kernel kernel10 { table rt_10; persist no; scan time 15; learn yes; device routes yes; kernel table 10; import where f1(net); export none; } ### KRT 20 table rt_20; # And this does, "kernel" protocol restarts without changing PS_1. define PS_1 = [ 192.168.0.0/16+ ]; function f2(prefix pfx) { if pfx ~ PS_1 then return false; return true; } There is nothing difficult in config: 2 functions f1() and f2() that do same thing except f2() matches specified as parameter prefix to a defined constant of type prefix set (PS_1). Starting bird, and invoking three times on console command to reconfigure bird (birdc configure) without altering configuration file I get following in my syslog: -------------------------------------------------------------------------------- Aug 21 18:50:54 gw1 bird: Started Aug 21 18:50:59 gw1 bird: Reconfiguring Aug 21 18:50:59 gw1 bird: Reloading protocol kernel20 Aug 21 18:50:59 gw1 bird: Restarting protocol kernel20 Aug 21 18:50:59 gw1 bird: Reconfigured Aug 21 18:51:08 gw1 bird: Reconfiguring Aug 21 18:51:08 gw1 bird: Reloading protocol kernel20 Aug 21 18:51:08 gw1 bird: Restarting protocol kernel20 Aug 21 18:51:08 gw1 bird: Reconfigured Aug 21 18:51:08 gw1 bird: Reconfiguring Aug 21 18:51:08 gw1 bird: Reloading protocol kernel20 Aug 21 18:51:08 gw1 bird: Restarting protocol kernel20 Aug 21 18:51:08 gw1 bird: Reconfigured Same thing can be reproduced with other protocols. This is not wery good to restart protocol when no REAL things changed in its filter, as it purges all routes from kernel table, and reinstalls them again causing flap when huge number of routes needed to be reinstalled. Can some one explain to me this behavior of BIRD? Does this mean that usage of constats with type prefix set is not recommended? Thanks for your support. -- SP5474-RIPE Sergey Popovich

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"gw" attribute assignment in filter invalidates routes learned via BGP, static, and possibly others?
by Sergey Popovich 27 Sep '13

27 Sep '13

Hello! Another issue I spot last time: assigning value in protocol export filter invalidates route and prevents its from being installed in KRT. Simple config to test this issue: ---------------------------------------- ### SYSTEM # ip link add dev lo255 type dummy # ip link set up dev lo255 # ip -4 addr add 192.0.2.254/24 dev lo255 # ip -4 addr add 172.16.2.254/24 dev lo255 # ip link set up dev eth0 # ip -4 addr add 192.168.1.2/24 dev eth0 ### BIRD router id 10.10.10.10; protocol device devices { scan time 120; } # Main routing table (master), mapped to ipt_main kernel table. # ipt_main == 254 (see /etc/iproute2/rt_tables) protocol kernel kernel254 { persist no; scan time 120; learn no; device routes no; kernel table ipt_main; import none; export all; } protocol direct direct254 { interface "lo255", "eth0"; } protocol static static254_test { # If "via" is one from "lo255" subnets (172.16.2.5 for example: # everything is correct and route installed by "kernel254" route 10.0.0.0/24 via 192.168.1.1; import filter { # This causes route invalidation, "gw" points to 192.0.2.5, # but interface is still "eth0" (see birdc output below). gw = 192.0.2.5; accept; }; export none; }; protocol static static254 { # rs1, rs2 route 192.168.254.1/32 via 192.168.1.1; route 192.168.254.2/32 via 192.168.1.1; } # AS65001, peering with Route Server(s), RS template bgp tl_bgp254_as65001 { start delay time 10; connect retry time 60; startup hold time 30; keepalive time 10; hold time 30; capabilities yes; advertise ipv4 yes; enable route refresh yes; enable as4 yes; gateway recursive; multihop 4; local 192.168.1.2 as 65010; import filter { # This causes route invalidation, "gw" points to 192.0.2.5, but # interface is still "eth0" (see birdc output below). gw = 192.0.2.5; accept; }; export none; } protocol bgp bgp254_as65001_rs1 from tl_bgp254_as65001 { neighbor 192.168.254.1 as 65001; } protocol bgp bgp254_as65001_rs2 from tl_bgp254_as65001 { neighbor 192.168.254.2 as 65001; } Here is output from birdc and ip-route(8): ---------------------------------------------------- ### common ## 192.0.2.0/24, lo255 $ birdc 'show route for 192.0.2.5 all' BIRD 1.3.11 ready. 192.0.2.0/24 dev lo255 [direct254 12:45] * (240) Type: device unicast univ $ ip -4 route show match 192.0.2.5/32 192.0.2.0/24 dev lo255 proto kernel scope link src 192.0.2.254 ## 172.16.2.0/24, lo255 $ birdc 'show route for 172.16.2.5 all' BIRD 1.3.11 ready. 172.16.2.0/24 dev lo255 [direct254 13:00] * (240) Type: device unicast univ $ ip -4 route show match 172.16.2.5/32 172.16.2.0/24 dev lo255 proto kernel scope link src 172.16.2.254 ## 192.168.1.0/24, eth0 $ birdc 'show route for 192.168.1.0/24 all' BIRD 1.3.11 ready. 192.168.1.0/24 dev eth0 [direct254 12:45] * (240) Type: device unicast univ $ ip -4 route show match 192.168.1.2/32 192.168.1.0/24 dev eth0 proto kernel scope link src 192.168.1.254 ### static ## 10.0.0.0/24 $ birdc 'show route for 10.0.0.0/24 all' BIRD 1.3.11 ready. 10.0.0.0/24 via 192.0.2.5 on eth0 [static254_test 13:19] ! (200) Type: static unicast univ $ ip -4 route show exact 10.0.0.0/24 ### BGP $ birdc 'show route for 10.0.0.0/8 all' BIRD 1.3.11 ready. 10.0.0.0/8 via 192.0.2.5 on eth0 [bgp254_as65001_rs1 13:00 from 192.168.254.1] ! (100/0) [AS1011i] Type: BGP unicast univ BGP.origin: IGP BGP.as_path: 65001 1011 BGP.next_hop: 192.168.1.1 BGP.local_pref: 100 BGP.community: (1001,65010) (1001,1001) via 192.0.2.5 on eth0 [bgp254_as65001_rs2 13:00 from 192.168.254.2] (100/0) [AS1011i] Type: BGP unicast univ BGP.origin: IGP BGP.as_path: 65001 1011 BGP.next_hop: 192.168.1.1 BGP.local_pref: 100 BGP.community: (1001,65010) (1001,1001) $ ip -4 route show exact 10.0.0.0/8 --------------------------------------------------------------------------------------- This is probably due to not updating iface, nexthops (multihop config) and other fields of "rta" struct. Provided patch in attachment tries to address this issue by calling rta_set_recursive_next_hop() in filter/filter.c to properly assign to "gw" attribute. Special cases for bgp and static protocols was taken to use "igp table" configuration parameter if present (tested, and found working with static protocol, probably some with bgp). Patch tested in my configuration and works wery well for both static and bgp protocols. --------------------------------------------------------------------------------------- Brief explanation why "gw" attribute might be wery important (at least in my case). There is common technique to stop DDoS in large ISP network: blackholing. However implementations of this might wary from vendor to vendor. In BIRD simplest way to implement this is to set "dest" attribute to something like RTD_BLACKHOLE, and all other route attributes gets deleted (gw, iface, ...). Route installed in KRT as blackhole. Everything is ok with this setup, but sometimes searching blackhole route might give some surprises: you trace path to blackholed destination and gets nothing(???) from your gateway, as it drops packets destined to blackhole route without any notification (in case of trace path without sending ICMP Time To Live Exceeded). And what if you trace from some core router? And heres another blackholing technique comes: use looped back interface to drop packets. In this case we setup some system looped back interface (in Linux this is dummy interface type), configure some network on it (say something 192.0.2.0/24), And instead of setting blackholed route type to RTD_BLACKHOLE we change its "gw" to any address within subnet assigned on looped back interface. Thats servers same as route with blackhole type, but behaves differently on trace paths: router sends ICMP Time To Live Exceeded messages from its incoming interface address indicating last hop before dropping blackholed traffic. This has no impact on DDoS traffic, except it transmitted to looped back interface instead of being dropped immediately after matching route and wasting few CPU cycles. -- SP5474-RIPE Sergey Popovich

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Re: OSPF: LSA disappeared
by Bao Nguyen 21 Sep '13

21 Sep '13

Just want to add to this thread that I'm seeing this behavior on BIRD as well, I'm seeing this on all the machines that I've installed. From the timer, it appeared to happened every 5 seconds.... root@sje17:~# birdc -v 0001 BIRD 1.3.4 ready. Jan 8 02:34:30 sje17 bird: OSPF: LSA disappeared (Type: 0005, Id: 10.25.206.123, Rt: 10.25.15.11) Jan 8 02:34:30 sje17 bird: OSPF: LSA disappeared (Type: 0005, Id: 10.25.205.147, Rt: 10.25.15.17) Jan 8 02:34:30 sje17 bird: OSPF: LSA disappeared (Type: 0001, Id: 10.25.15.3, Rt: 10.25.15.3) Jan 8 02:34:30 sje17 bird: OSPF: LSA disappeared (Type: 0001, Id: 10.25.15.4, Rt: 10.25.15.4) Jan 8 02:34:30 sje17 bird: OSPF: LSA disappeared (Type: 0002, Id: 10.25.202.1, Rt: 10.25.239.11) Jan 8 02:34:30 sje17 bird: OSPF: LSA disappeared (Type: 0002, Id: 10.25.201.1, Rt: 10.25.239.10) Jan 8 02:34:30 sje17 bird: OSPF: LSA disappeared (Type: 0002, Id: 10.25.201.13, Rt: 10.25.239.10) Jan 8 02:34:30 sje17 bird: OSPF: LSA disappeared (Type: 0005, Id: 10.25.201.12, Rt: 10.25.10.4) Jan 8 02:34:35 sje17 bird: OSPF: LSA disappeared (Type: 0005, Id: 10.25.206.123, Rt: 10.25.15.11) Jan 8 02:34:35 sje17 bird: OSPF: LSA disappeared (Type: 0005, Id: 10.25.205.147, Rt: 10.25.15.17) Jan 8 02:34:35 sje17 bird: OSPF: LSA disappeared (Type: 0001, Id: 10.25.15.3, Rt: 10.25.15.3) Jan 8 02:34:35 sje17 bird: OSPF: LSA disappeared (Type: 0001, Id: 10.25.15.4, Rt: 10.25.15.4) Jan 8 02:34:35 sje17 bird: OSPF: LSA disappeared (Type: 0002, Id: 10.25.202.1, Rt: 10.25.239.11) Jan 8 02:34:35 sje17 bird: OSPF: LSA disappeared (Type: 0002, Id: 10.25.201.1, Rt: 10.25.239.10) Jan 8 02:34:35 sje17 bird: OSPF: LSA disappeared (Type: 0002, Id: 10.25.201.13, Rt: 10.25.239.10) Jan 8 02:34:35 sje17 bird: OSPF: LSA disappeared (Type: 0005, Id: 10.25.201.12, Rt: 10.25.10.4) -bn 0216331C

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BGP syslog
by Jimmy Halim 05 Sep '13

05 Sep '13

Hi guys, Can I confirm with you guys that syslog is only logging the event for BGP Notification errors only? I mean, it does not log the BGP session up and down event? Thanks in advance! Cheers, Jimmy

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Simple load balancing setup with RIP
by jarek 05 Sep '13

05 Sep '13

Hello! Can someone help me with simple load balancing setup ? I tried to do it myself, but failed. This is my case: /--------------\ | NET A | \--------------/ | | +-------eth0--------+ |Router A with bird | +---eth1-----eth2---+ | | Link 1 Link 2 | | /----GW1------GW2----\ | | | NET B | | | \--------------------/ I need that hosts from NET A will connect to hosts in NET B. NET A is my network with router A as default GW. NET B is commercial network with RIP. NET A must be exported over RIP to NET B. Link 1 and Link 2 should work with load balancing and fail over. best regards Jarek

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IPv6 and trigger
by Miłosz Oller 30 Aug '13

30 Aug '13

Hi I have configured IPv6 with radv. It works properly on one router. I have two routers with HA. In documentation is 'trigger prefix' in radv protocol. My config on routers: protocol radv dc { interface "bond1.10" { max ra interval 5; managed no; prefix 2001:67c:2ad8::/64 { autonomous off; }; prefix 2001:67c:2ad8:1::/64 { autonomous off; }; }; trigger 2001:067c:2ad8::/48; } I moved 2001:067c:2ad8:ffff::ffff/48 - bond1 and 2001:67c:2ad8::1/64 - bond1.10 on router 1 to router 2. And it doesn't work. Hosts don't have route to global network. How to configure it properly? -- Miłosz Oller

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[PATCH 1/3] PATCH FLX: Add command line option for specifying the pid file
by Exceliance 28 Aug '13

28 Aug '13

--- sysdep/unix/main.c | 31 +++++++++++++++++++++++++++++-- 1 file changed, 29 insertions(+), 2 deletions(-) diff --git a/sysdep/unix/main.c b/sysdep/unix/main.c index bd80ba2..c0b2b22 100644 --- a/sysdep/unix/main.c +++ b/sysdep/unix/main.c @@ -548,16 +548,17 @@ signal_init(void) * Parsing of command-line arguments */ -static char *opt_list = "c:dD:ps:u:g:"; +static char *opt_list = "c:dD:ps:u:g:P:"; static int parse_and_exit; char *bird_name; static char *use_user; static char *use_group; +static char *pid_file; static void usage(void) { - fprintf(stderr, "Usage: %s [-c <config-file>] [-d] [-D <debug-file>] [-p] [-s <control-socket>] [-u <user>] [-g <group>]\n", bird_name); + fprintf(stderr, "Usage: %s [-c <config-file>] [-d] [-D <debug-file>] [-p] [-s <control-socket>] [-u <user>] [-g <group>] [-P <pid-file>]\n", bird_name); exit(1); } @@ -621,6 +622,28 @@ get_gid(const char *s) return gr->gr_gid; } +static inline void +set_pid(const char *s) +{ + int fd; + char pid[6]; + + if (!s) + return; + + memset(pid, 0, sizeof(pid)); + + if((fd=open(s, O_WRONLY|O_CREAT, 0664)) == -1) + die("Cannot open pid file '%s'", s); + + snprintf(pid, sizeof(pid), "%u", getpid()); + + if(write(fd, pid, sizeof(pid)) == -1) + die("Cannot write pid file '%s'", s); + + return; +} + static void parse_args(int argc, char **argv) { @@ -662,6 +685,9 @@ parse_args(int argc, char **argv) case 'g': use_group = optarg; break; + case 'P': + pid_file = optarg; + break; default: usage(); } @@ -733,6 +759,7 @@ main(int argc, char **argv) dup2(0, 2); } + set_pid(pid_file); signal_init(); #ifdef LOCAL_DEBUG -- 1.8.1.1 --Multipart=_Tue__24_Sep_2013_16_35_48_+0200_AMU0Imo+Flc+Ayzu Content-Type: text/x-diff; name="0003-FEAT-Add-protocol-volatile.patch" Content-Disposition: attachment; filename="0003-FEAT-Add-protocol-volatile.patch" Content-Transfer-Encoding: 7bit

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OSPF generate default route
by Slawa Olhovchenkov 26 Aug '13

26 Aug '13

I have configuration problem: how I can generate default route in OSPF area? Generate, not redistribute from static kernel route or other routing protocol. Generate, not installed into kernel routeng table. Same as for Cisco 'default-information originate always'. Next question: conditional advertise default route (for example -- if present announce in BGP to some network).

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