August 2014 - Bird-users

Log rotation support
by Alexander Demenshin 26 Aug '14

26 Aug '14

Hi, It looks like that there is no log rotation possible when logging to files. Though I can fix it locally, it would be nice to include support for this in the future versions, as log files may be quite large and not everyone is using syslog. It could be done using birdc or some (unused yet) signal. Thank you! -- With best regards, Alexander.

3 4

Reloading static/direct/device/kernel protocols via birdc fails
by Alexander Demenshin 22 Aug '14

22 Aug '14

Hi, When I am attempting to reload kernel, static, direct or device protocol via birdc, I always get message like this "krt_main: reload failed", while in the log file I see just reloading message: <INFO> Reloading protocol krt_main For pipe, bgp and ospf instances there is only "reloading" message. Is this a bug, feature or something else? PS: I need reload to force bird to rescan specific kernel table. Thank you! -- With best regards, Alexander.

2 2

changes somewhere between 1.3.9 and 1.4.0
by Mikhail A. Grishin 22 Aug '14

22 Aug '14

Hi, We found that in 1.4.0 and later versions our approach to see rejected BGP routes for IXP customers stop working. This worked fine in 1.3.9 and earlier versions: --------- [18:44:27]ekt-rsm1% echo 'show route protocol R2854x1' | birdc | wc -l 238 [15:58:45]ekt-rsm1% echo 'show route protocol R2854x1 table T2854x1' | birdc | wc -l 245 ---------- Diffs between this two outputs - rejected routes. At 1.4.0 and later we see the same numbers: [16:00:26]ekt-rsm2# echo 'show route protocol R2854x1 table T2854x1' | birdc | wc -l 245 [16:08:51]ekt-rsm2# echo 'show route protocol R2854x1' | birdc | wc -l 245 Can you tell us, what changed? And how to restore old behavior? -- Wbr, Mikhail MSK-IX

2 1

Unknown LSA type from x.x.x.x
by Eric Cables 22 Aug '14

22 Aug '14

Running BIRD v1.4.4 I'm seeing a lot of these error messages: bird: Unknown LSA type from x.x.x.x Is this anything to worry about? I don't see any issues affecting BIRD, but it is filling up log files. -- Eric Cables

2 1

explicitly setting rte->next = null
by Nic Cave-Lynch 22 Aug '14

22 Aug '14

Hi People I've been trying to find a segfault in a custom protocol I've been writing. I've finally tracked it down to a situation where bgp protocol, in bgp_rte_update, is calling rte_get_temp but not setting -> next to null, leaving it at whatever was left in RAM when the memory was allocated. Later, I see it's not null and try to access the ->next and eventually trigger a segfault. I've looked at the code and I can't see any reason why ->next shouldn't be set to null. So, does anyone know if this is going to cause problems later? The attached patch implements my change. I wonder if it might be better to explicitly set the rte pointed to by rte_get_temp to zero before using and returning it. I didn't want to make that change in case there are really good reasons why not. Cheers Nic C-L

2 2

Constants can't contain other constants?
by Michael Fincham 21 Aug '14

21 Aug '14

Hi everyone, I'm presently investigating BIRD as a (much appreciated!) replacement for Quagga and running in to some behaviour that isn't clear from reading the documentation. I'm looking at ways to consistently template BGP communities received from / sent to peers across multiple routers, and have attempted this: define test_international = (test_asn, 90); define test_national = (test_asn, 100); define test_ix = (test_asn, 200); define test_bilat = (test_asn, 300); define test_customer = (test_asn, 400); define test_infrastructure = (test_asn, 500); define test_send_to_transit = [test_blackhole]; define test_send_to_ix = []; define test_send_to_customer = [ test_international, test_national, test_ix, test_bilat, test_customer, test_infrastructure ]; With a view to later making a call to 'filter' in the BGP export filter facing the test customer: bgp_community.filter(test_send_to_customer); However loading this configuration in BIRD produces an error: bird> configure Reading configuration from /etc/bird/bird.conf /etc/bird/template/common.conf, line 84: Number expected Line 84 being the line shown above "define test_send_to_transit = [test_blackhole];". This suggests to me that one cannot define a constant including another existing constant in this manner? If so, is the best approach instead to define constants for individual communities and use re-usable 'functions' to group them logically? Suggestions heartily appreciated :) -- Michael

2 3

BGP Keepalive timer wedging
by Chris Caputo 20 Aug '14

20 Aug '14

At the Seattle IX we are using BIRD 1.4.4 for our native (non-VM) route servers. With one particular IPv4 peer, on two different route servers, I am seeing "Keepalive timer" count down to zero and then becoming wedged/stalled. Tcpdump fails to show a keepalive message being sent, while it does show them being received from the peer. We are using the default timer values. 2014-08-20 00:30:08 <TRACE> ex: Incoming connection from 206.81.80.xx (port 25663) accepted 2014-08-20 00:30:08 <TRACE> ex: Sending OPEN(ver=4,as=33108,hold=240,id=xxxxxxxx) 2014-08-20 00:30:09 <TRACE> ex: Got OPEN(as=xxxxx,hold=180,id=xxxxxxxx) 2014-08-20 00:30:09 <TRACE> ex: Sending KEEPALIVE 2014-08-20 00:30:09 <TRACE> ex: Got KEEPALIVE 2014-08-20 00:30:09 <TRACE> ex: BGP session established 2014-08-20 00:30:09 <TRACE> ex: Connected to table master 2014-08-20 00:30:09 <TRACE> ex: State changed to feed In the above, "Sending KEEPALIVE" does correspond to an outgoing keepalive packet, per tcpdump. Actually, two are sent on session startup, and then no more. "show protocols all ex" shows: Hold timer: 126/180 Keepalive timer: 0/60 etc.: Hold timer: 119/180 Keepalive timer: 0/60 with Hold timer getting updated over time, but the Keepalive timer doesn't change after it has its initial countdown to zero. The peer eventually signals "ex: Received: Hold timer expired" once it goes 180 seconds without a BGP update, since it also hasn't gotten any keepalive messages. I've looked at the code and haven't found a problem. The other 64 similarly configured peers on the route server are working fine. Has anyone seen this or have any suggestions? Thanks, Chris Seattle Internet Exchange

2 2

Allowing multiple instances of kernel protocol to use same table
by Alexander Demenshin 18 Aug '14

18 Aug '14

Hi, Is there any specific reason why each instance of kernel protocol must use unique table? What I want to achieve is to export different protocols (OSPF, BGP etc) to different kernel tables, but the only way I can do this currently is to use pipe, instead of export filter only. My concern is duplication of data - BGP table has over 500k routes, so keeping this in master *and* piping to another one for kernel export is a waste of resources (both RAM and CPU). Thank you! -- With best regards, Alexander.

3 5

Removing device-bound routes when interface is going down
by Alexander Demenshin 18 Aug '14

18 Aug '14

Hi (again), I've encountered a problem which is (most likely) is caused by a bug in the Linux kernel, but significantly affects routing handling in bird (everything else like quagga is most likely also affected). When route is added manually/externally to the kernel, and bound to specific interface, like this: $ ip route add 10.1.1.0/24 dev eth0 ...it is correctly identified by bird (via async netlink message), but when the interface goes down, this route is not deleted, as there is no corresponding netlink message (tested on most recent kernel, 3.16.1, and also on older 3.11, this happens only on if-down event, manual deletion works fine). Since bird does not see the route removal, it is still kept in the routing table, thus, it is still announced via OSPF (in my particular case), however the kernel knows nothing about this. Obviously, it is possible to set up periodic scanning of kernel table with small interval, but even then, this removal will not be instant, and additionally, it introduces additional CPU usage - even if the table in question is small by itself, but there is another huge table, this scan will consume significant time, in my case - it takes 0.3s to dump main table (~10 entries), all due to huge BGP table (~500k entries), thus scanning every 10 seconds will consume 3% CPU (mostly for nothing, as this kind of changes are relatively seldom). Fixing this problem in the mainstream kernel (if this is indeed unintentional behavior) will clearly take ages, but it could be easily solved in bird itself - if interface is going down, all routes pointing to this device must be removed (not only direct and static routes - where it works perfectly). I feel that this workaround is quite easy to implement, but not sure where exactly to look, thus I'll be really grateful for right directions :) Thank you! -- With best regards, Alexander.

4 6

BGP Filtering question
by Eloi Carbó Solé 18 Aug '14

18 Aug '14

Hi everyone, I am trying to do something that I think that should be so easy but I am not success yet. In IPv4 I need to know if there is any possibility to execute OS commands and receive its output (in filters or functions) owing to receive the list of dev names to accept (concretely in a OpenWRT shell or similar). An example of the routes I want to accept is: 10.201.192.0/24 dev bmxOut_GSoC-0a proto static metric 1024 Otherwise, my other possiblity is to use statically the device name: bmx_____, using the pattern "bmx*" to filter them (it is possible?), but I am not really sure if there is a "dev" option, if I may use "ifname" (it is outgoing iface, so I suppose that no) or something like to check it. Best regards, -- Eloi Carbó

2 1