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Route aggregation
by Paul Donohue 31 Dec '16

31 Dec '16

I see that Alexander V. Chernikov wrote a patch to implement route aggregation back in 2012, and Ondrej Zajicek was planning on merging it with some changes: http://bird.network.cz/pipermail/bird-users/2013-January/003337.html However, it does not look like this was ever actually merged, and the latest version of the patch ("Version 7") seems to be missing from the mailing list archives. Does anyone know where I can find the latest version of this patch? Is there any chance this patch will ever be merged? Thanks! -Paul

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having trouble getting default to be added to route table, says filtered out
by Jerry Scharf 31 Dec '16

31 Dec '16

Hi, I did a quick look at the archives and didn't see exactly what I was trying discussed. I have some border machines running bird connected to junpiers that are bgp peering with our ISPS. I have the junipers set up such that they generate a default route and send it to the border machines. I want the border machines to put it in the system routing table and then pass that on to the inside systems. Everyone is speaking bgp, one AS for the outside and one for the inside. I am running 1.4.5 (centos 7 release) here are the parts of the config that are involved: filter load_default { if net = [0.0.0.0/0] then accept; else reject; } template bgp toedge { description "bgp to edge/ISP as"; local as 65401; direct; export filter outside_only; import filter load_default; allow local as; bfd on; source address 172.18.2.10; } protocol bgp edgeA from toedge { neighbor 172.18.2.1 as 65401; debug all; } protocol bgp edgeB from toedge { neighbor 172.18.2.2 as 65401; } here's the debug output: 2016-12-30 11:28:53 <INFO> Started 2016-12-30 11:28:53 <TRACE> edgeA: Started 2016-12-30 11:28:53 <TRACE> edgeA: Connect delayed by 5 seconds 2016-12-30 11:28:57 <TRACE> edgeA: Connecting to 172.18.2.1 from local address 172.18.2.10 2016-12-30 11:28:57 <TRACE> edgeA: Connected 2016-12-30 11:28:57 <TRACE> edgeA: Sending OPEN(ver=4,as=65401,hold=240,id=01020304) 2016-12-30 11:28:57 <TRACE> edgeA: Got OPEN(as=65401,hold=90,id=ac120001) 2016-12-30 11:28:57 <TRACE> edgeA: Sending KEEPALIVE 2016-12-30 11:28:57 <TRACE> edgeA: Got KEEPALIVE 2016-12-30 11:28:57 <TRACE> edgeA: BGP session established 2016-12-30 11:28:57 <TRACE> edgeA: Connected to table master 2016-12-30 11:28:57 <TRACE> edgeA: State changed to feed 2016-12-30 11:28:57 <TRACE> edgeA < added 198.48.100.20/32 dev lo 2016-12-30 11:28:57 <TRACE> edgeA < added 198.48.100.21/32 dev lo 2016-12-30 11:28:57 <TRACE> edgeA < added 8.25.217.22/32 dev lo 2016-12-30 11:28:57 <TRACE> edgeA: State changed to up 2016-12-30 11:28:57 <TRACE> edgeA: Sending UPDATE 2016-12-30 11:28:57 <TRACE> edgeA: Sending End-of-RIB 2016-12-30 11:28:57 <TRACE> edgeA < filtered out 10.200.32.0/28 via 10.200.0.3 on eth4 2016-12-30 11:28:57 <TRACE> edgeA < filtered out 10.200.0.1/32 via 10.200.0.3 on eth4 2016-12-30 11:28:57 <TRACE> edgeA < filtered out 10.200.16.1/32 via 10.200.0.3 on eth4 2016-12-30 11:28:57 <TRACE> edgeA: Got KEEPALIVE 2016-12-30 11:28:57 <TRACE> edgeA: Got UPDATE 2016-12-30 11:28:57 <TRACE> edgeA: Got End-of-RIB 2016-12-30 11:28:57 <TRACE> edgeA: Got UPDATE 2016-12-30 11:28:57 <TRACE> edgeA > filtered out 0.0.0.0/0 via 172.18.2.1 on eth1 2016-12-30 11:28:58 <TRACE> edgeA < filtered out 10.200.16.1/32 via 10.200.16.3 on eth5 As you can see (second line from the bottom of the debug), it got the default advertisement from the peer and bird says it filtered it out (the other filters are correct.) I set allow-local-as for the peer and have a filter that is supposed to match and accept exactly the route that says was filtered. what am I doing wrong? BTW, I am also having trouble with setting localpref in a filter. here's the config pieces: function is_primary() { return net = [198.48.100.10/32, 198.48.100.20/32]; } function is_secondary() { return net = [8.25.217.10/32, 8.25.217.21/32]; } function is_tertiary() { return net ~ [198.48.100.0/24+, 8.25.217.0/24+]; } filter outside_only { if is_primary() then bgp_local_pref=100; else if is_secondary() then bgp_local_pref=80; else if is_tertiary() then bgp_local_pref=60; if net_outside() then accept; else reject; } They all end up on the junipers with locappref of 60. How do I do this right? thanks in advance, jerry

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OSPF: Route attribute "ospf_tag" lost between different OSPF instances
by markus/grundmann 28 Dec '16

28 Dec '16

Hello! I believe that I'm a user with BIRD experiences but current I have no idea why the attribute "ospf_tag" from one OSPF instance to another is unavailable. In this real life example you can see that I receive a default route from my ISP that is tagged with "7b". This tag is not visible on the VPN client. I use for each VPN network a OSPF instance with some filter rules but only static routes (Core VPN) with a "ospf_tag" are usable to filter like "if ospf_tag = xyz then ..." How can I exchange routes based on a "ospf_tag" between two or more OSPF router instances? [Core VPN Router] BIRD 1.6.0 ready. 0.0.0.0/0 via 82.206.X.33 on lagg0 [titan 2016-12-25] * E2 (150/5/10) [7b] [217.173.X.190] [VPN Client] BIRD 1.6.0 ready. 0.0.0.0/0 via 10.82.16.1 on tun2 [lte 00:28:10] * E1 (150/5) [82.206.X.34] via 10.82.17.1 on tun3 [umts 00:28:11] E1 (150/10) [82.206.X.34] -- Static-Tagging Works Fine --- route 11.0.0.0/8 via 82.206.X.33 { ospf_tag=16170; }; filter openvpn9x16171_export { if net = 0.0.0.0/0 then { ospf_metric1 = SEC_M1_VPN; ospf_metric2 = SEC_M2_VPN; accept; } // [...] if ospf_tag = 16171 then { <== WORKS FINE because static route ospf_metric1 = SEC_M1_VPN; ospf_metric2 = SEC_M2_VPN; accept; } reject; } -- Best regards, Markus

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Version 1.6.3
by Ondrej Filip 23 Dec '16

23 Dec '16

Dear users, a new version of the 1.6.x branch is out: Version 1.6.3 o Large BGP communities o BFD authentication (MD5, SHA1) o SHA1 and SHA2 authentication for RIP and OSPF o Improved documentation o Several bug fixes This is meant to be a stable version. An upgrade is recommended. Enjoy it! And Merry Xmas! Ondrej

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Re: BIRD patches for IP-in-IP
by Mohammad Banikazemi 22 Dec '16

22 Dec '16

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Dynamic cost?
by Mike Jones 22 Dec '16

22 Dec '16

Hi, I have an OSPF based network using bird for routing the core and it seems to work fine, however the network is geographically diverse and some of the routing is sub-optimal. Specifically, the default route is going shortest hops rather than lowest latency. What I would like to do is have the OSPF cost reflect the latency of the link, however I am having a problem coming up with a scalable/automated way of doing this. As far as I can tell there is no built in "latency to peer" I can reference? I could configure a manual entry for each peer in the config file, however that doesn't seem very manageable, even with some kind of script to generate the config file. >From what I can gather there is no way for a filter to reference an external file/database/script to adjust the routes on import. I even considered a convoluted approach of having a script inject the peers IP address in to a special kernel table and using the route metric to feed numbers in to bird, but couldn't find a way of storing the data and referencing it on a later route lookup. Basically what I want is that when an OSPF peer comes up I ping it then set the cost for all routes received from that neighbour to the latency (with some basic sanity like a min and max). I don't expect the latency to vary much once a link is up, however I do need to auto-discover new peers appearing on the network. Any ideas? Thanks - Mike Jones

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BIRD 1.6.2 removes IPv6 kernel routes
by Robert Sander 21 Dec '16

21 Dec '16

Hi, I have an issue with BIRD 1.6.2 from http://bird.network.cz/debian/ on Debian jessie: When bird6 is running and I "ifup" an interface with a static IPv6 address the address is added but no IPv6 route in the associated network via that interface. When bird6 is not running everything works. It looks like bird6 1.6.2 is eating IPv6 routes set by the kernel. I have not encountered this issue with the IPv4 bird daemon. After downgrading to bird 1.4.5 from Debian jessie everything works as expected. What information do you need? Regards -- Robert Sander Heinlein Support GmbH Schwedter Str. 8/9b, 10119 Berlin http://www.heinlein-support.de Tel: 030 / 405051-43 Fax: 030 / 405051-19 Zwangsangaben lt. §35a GmbHG: HRB 93818 B / Amtsgericht Berlin-Charlottenburg, Geschäftsführer: Peer Heinlein -- Sitz: Berlin

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bird incorrectly merging next hops
by Bernardo Figueiredo 15 Dec '16

15 Dec '16

Hi, At our network we use bird in all our Linux routers so they talk OSPF. Recently we added a new router appliance(not Linux) to the backbone and most of the bird routers showed wrong next hops for some routes. At first we tought that the problem might be caused by a bug in the appliance making it send bad LSAs, but debugging the ospf packets and looking at other non-bird router appliances made us certain that the fault was in bird. After looking through the code we found that the bug is in function 'ospf_ext_spf' in file 'proto/ospf/rt.c'. The variable 'nfa' of type 'struct orta' is not totally cleaned before each start of the 'WALK_SLIST' loop, and can have a wrong value of 'nfa.nhs_reuse = 1' instead of 'nfa.nhs_reuse = 0', which is what triggers the bug. The fix is to put the declaration of 'orta nfa = {};' inside the loop, so the variable is clean at the start of each loop. Alternatively at the start of each loop you could set 'nfa.nhs_reuse = 0'. The bug only occurs when the following options are in bird.conf: ecmp yes; merge external yes; At least from what I saw the bug affects versions '2.0', '1.6.2' and '1.5'. If some of the explanation is not clear please tell me and I'll try to write it better. I'll provide a more in-depth explanation now: the relevant code is: the code is 'tagged' with 'x->' which are the relevant points for trigerring the bug static void ospf_ext_spf(struct ospf_proto *p) { ort *nf1, *nf2; 0->orta nfa = {}; ip_addr rtid; OSPF_TRACE(D_EVENTS, "Starting routing table calculation for ext routes"); WALK_SLIST(en, p->lsal) { /*not showing LSA validation*/ rtid = ipa_from_rid(en->lsa.rt); 1-> nf1 = fib_find(&atmp->rtr, &rtid, MAX_PREFIX_LENGTH); /*not showing other validations*/ if (!rt.fbit) { nf2 = nf1; 2-> nfa.nhs = nf1->n.nhs; br_metric = nf1->n.metric1; } else { nf2 = ospf_fib_route(&p->rtf, rt.fwaddr, MAX_PREFIX_LENGTH); if (!nf2) { continue; } /*not showing some validations*/ nfa.nhs = nf2->n.nhs; br_metric = nf2->n.metric1; if (has_device_nexthops(nfa.nhs)) { nfa.nhs = fix_device_nexthops(p, nfa.nhs, rt.fwaddr); 3-> nfa.nhs_reuse = 1; } } /*not showing setting other attributes in 'nfa'*/ 4-> ri_install_ext(p, rt.ip, rt.pxlen, &nfa); } } static inline void ri_install_ext(struct ospf_proto *p, ip_addr prefix, int pxlen, const orta *new) { 5->ort *old = (ort *) fib_get(&p->rtf, &prefix, pxlen); int cmp = orta_compare_ext(p, new, &old->n); if (cmp > 0) { ort_replace(old, new); } else if (cmp == 0) { 6-> ort_merge_ext(p, old, new); } } static void ort_merge_ext(struct ospf_proto *p, ort *o, const orta *new) { orta *old = &o->n; if (old->nhs != new->nhs) { 7-> old->nhs = mpnh_merge(old->nhs, new->nhs, old->nhs_reuse, new- >nhs_reuse, p->ecmp, p->nhpool); old->nhs_reuse = 1; } /* not showing code that sets other attributes */ } struct mpnh * mpnh_merge(struct mpnh *x, struct mpnh *y, int rx, int ry, int max, linpool *lp) { struct mpnh *root = NULL; struct mpnh **n = &root; while ((x || y) && max--) { int cmp = mpnh_compare_node(x, y); if (cmp < 0) { *n = rx ? x : mpnh_copy_node(x, lp); x = x->next; } else if (cmp > 0) { 8-> *n = ry ? y : mpnh_copy_node(y, lp); y = y->next; } else { 9-> *n = rx ? x : (ry ? y : mpnh_copy_node(x, lp)); x = x->next; y = y->next; } n = &((*n)->next); } *n = NULL; return root; } conditions to trigger the bug: * while in the loop there must be a LSA that has a forwading address which routes satisfy the conditions to trigger 'has_device_nexthops' so 'nfa.nhs_reuse' is set to 1, this corresponds to '3->'. Afterwards the bug could be trigger in any LSA that has the following properties: * LSA forwarding address equal to 0.0.0.0; so we set 'nfa' to the route to the router that sent the LSA. This last route is the one might be corrupted. This corresponds to '1->' and '2->'; * the route passes the validations to be installed in the OSPF routing table. This corresponds to '4->' * the old route that we had for the destination on the LSA is equally good to the new route that we are installing so we decide to merge them. This corresponds to '5->' and '6->' * The routes aren't the same instance so we decide to merge them. '7->' * While merging the next hop list we must compare at least one next hop from the 'new' route higher than a next hop from the 'old' route so we enter '8->' and wrongly not copy the next hop because 'ry = 1' due to 'nfa.nhs_reuse = 1'. This might also happen in '9->' if the next hops compare equal, but I haven't checked.

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LSA ID collision issue is seen with OSPF stub-networks configured and BIRD is acting as ABR
by naveen chowdary Yerramneni 13 Dec '16

13 Dec '16

Hi, *Issue Description*: LSA ID collision issue is seen with OSPF *stub-networks* configured and BIRD is acting as ABR *BIRD OSPF configuration*: · Part of 2 areas (say, area-0 and area-100) · Stub-networks are configured in area-0 *Code Flow*: 1. Stubnets are advertised to area-0 by generating router LSA ( LSA_T_RT). o ospf_disp() -> ospf_update_topology() -> ospf_originate_rt_lsa()->ospf_ originate_lsa() 2. Now, stubnets are added to top graph table (p->gr) with LSA type LSA_T_RT 3. When creating routing table, these stubnets are added to FIB ( p->rtf). o ospf_disp() -> ospf_rt_spf() -> ospf_rt_spfa() -> spfa_process_rt() -> add_network() -> ri_install_net() 4. When BIRD is acting as ABR then, walk through FIB(p->rtf) and send summary LSA (LSA_T_SUM_NET) with LSA mode as LSA_M_RTCALC. Also, nf pointer is set (stores fib node address) in top_hash_entry. o ospf_disp() -> ospf_rt_abr2() -> check_sum_net_lsa() -> ospf_originate_sum_net_lsa() ->ospf_originate_lsa() 5. Now, stubnets are added to top graph table (p->gr) with LSA type LSA_T_SUM_NET 6. Stubnets are removed from FIB(p->rtf) o ospf_disp() -> rt_sync() -> fib_delete() 7. Now, stubnets entries are still present in top graph table (Note: fib_delte() doesn't free the node, it just moves the fib node to free pool, fib_node pointer is still valid) 8. With any change in network, ospf_rt_spf()is called. In ospf_rt_reset(), LSA mode is updated fromLSA_M_RTCALC to LSA_M_STALE. 9. Again, steps 3-6 are repeated. In step-3, fib node pointer is changed and in step-4, fib node pointer comparison fails in ospf_originate_lsa()which is leading to LSA id collision. *Issue is resolved with below code change. *Please review the change and provide your comments. Also, please let me know if any other information is required. diff -rupN bird/proto/ospf/topology.c bird_modified/proto/ospf/topology.c --- bird/proto/ospf/topology.c 2016-11-28 05:14:19.582761752 -0800 +++ bird_modified/proto/ospf/topology.c 2016-11-28 05:14:01.270761752 -0800 @@ -278,7 +278,7 @@ ospf_originate_lsa(struct ospf_proto *p, if (!SNODE_VALID(en)) s_add_tail(&p->lsal, SNODE en); - if (!en->nf || !en->lsa_body) + if (!en->nf || !en->lsa_body || en->mode == LSA_M_STALE) en->nf = lsa->nf; Thanks, Naveen

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How does BIRD detect the connected network type for ospf neighbor
by Wei Huang 13 Dec '16

13 Dec '16

When I set my ospf interface eth1's address to be 10.2.1.2/30, neighbor router ethernet interface IP address to be 10.2.1.1/30, the neighbor shows it's PTP type: bird> sh ospf neighbors ospf_rdomain_0: Router ID Pri State DTime Interface Router IP 172.16.20.76 1 Full/PtP 00:35 vni-0 10.2.1.1 If I change the interfaces' IP address to be 10.2.1.x/24 or I force interface type to be bcast in Bird's ospf config, it shows as bird> sh ospf neighbors ospf_rdomain_0: Router ID Pri State DTime Interface Router IP 172.16.20.76 1 Full/DR 00:35 vni-0 10.2.1.1 My question is how does Bird detect the connected network type? Thanks, Wei

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