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Filter BGP route based on ospf_metric1 ?
by Robert Sander 24 Mar '22

24 Mar '22

Hi, Our routers speak OSPF and have a full mesh of BGP connections for our internal routes. This works quite well. One router sees the other through OSPF: 80.241.60.8/32 via 10.25.19.251 on bond0.19 [ospf1 2022-03-17] * I (150/2474) [80.241.60.8] Type: OSPF unicast univ OSPF.metric1: 2474 OSPF.metric2: 16777215 OSPF.tag: 0x00000000 OSPF.router_id: 80.241.60.8 The BGP session is established to 80.241.60.8 and e.g. this route is learned: 192.168.100.0/22 via 10.25.19.251 on bond0.19 [thor 2022-03-17 from 80.241.60.8] * (100/2474) [i] Type: BGP unicast univ BGP.origin: IGP BGP.as_path: BGP.next_hop: 80.241.60.8 BGP.local_pref: 100 In the first line the ospf_metric1 is shown: (100/2474) But when I try to filter on it (because I want to drop routes with a too high metric), the route attribute ospf_metric1 is "(void)". This seems to be because it's a BGP route and not an OSPF route. Is it somehow possible to achieve this? PS: This is with bird 1.6.8. Kindest Regards -- Robert Sander Heinlein Consulting 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 220009 B / Amtsgericht Berlin-Charlottenburg, Geschäftsführer: Peer Heinlein -- Sitz: Berlin

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[PATCH] Lib: accept 240.0.0.0/4 as a valid range
by Vincent Bernat 16 Mar '22

16 Mar '22

240.0.0.0/4 is marked as reserved and considered invalid by BIRD. At work, we are using this range internally since all RFC 1918 are full and 100.64.0.0/10 is already used too. BIRD complains loudly for each interface using this range. This change makes it possible to use this range. I have used scope "universe". But I would be happy with "site" too. While widely discussed, I don't think 240/4 will become routable on the Internet one day. As a bonus, I added some comments and unrolled a condition for each block. I also have added some hints for the compiler to avoid using jumps in the hotpath (tested on Godbolt, see https://godbolt.org/z/rGjz336K3) --- lib/ip.c | 31 ++++++++++++------------------- sysdep/config.h | 5 +++++ 2 files changed, 17 insertions(+), 19 deletions(-) diff --git a/lib/ip.c b/lib/ip.c index fcc72cafb4de..8f0f32d25d61 100644 --- a/lib/ip.c +++ b/lib/ip.c @@ -80,30 +80,23 @@ ip6_masklen(ip6_addr *a) } int -ip4_classify(ip4_addr ad) +ip4_classify(u32 a) { - u32 a = _I(ad); u32 b = a >> 24U; - if (b && b <= 0xdf) - { - if (b == 0x7f) - return IADDR_HOST | SCOPE_HOST; - else if ((b == 0x0a) || - ((a & 0xffff0000) == 0xc0a80000) || - ((a & 0xfff00000) == 0xac100000)) - return IADDR_HOST | SCOPE_SITE; - else - return IADDR_HOST | SCOPE_UNIVERSE; - } - - if (b >= 0xe0 && b <= 0xef) + if (unlikely(b == 0x00)) + return IADDR_INVALID; /* 0.0.0.0/8 This network */ + if (unlikely(b == 0x7f)) /* 127.0.0.0/8 Loopback */ + return IADDR_HOST | SCOPE_HOST; + if ((b == 0x0a) || /* 10.0.0.0/8 Private-use */ + ((a & 0xffff0000) == 0xc0a80000) || /* 192.168.0.0/16 Private-use */ + ((a & 0xfff00000) == 0xac100000)) /* 172.16.0.0/12 Private-use */ + return IADDR_HOST | SCOPE_SITE; + if (unlikely(b >= 0xe0 && b <= 0xef)) /* 224.0.0.0/4 Multicast */ return IADDR_MULTICAST | SCOPE_UNIVERSE; - - if (a == 0xffffffff) + if (unlikely(a == 0xffffffff)) /* 255.255.255.255 Limited broadcast */ return IADDR_BROADCAST | SCOPE_LINK; - - return IADDR_INVALID; + return IADDR_HOST | SCOPE_UNIVERSE; } int diff --git a/sysdep/config.h b/sysdep/config.h index b0531844af9f..4d73543c3894 100644 --- a/sysdep/config.h +++ b/sysdep/config.h @@ -30,6 +30,11 @@ */ #include "sysdep/paths.h" +/* Likely/unlikely macros */ + +#define likely(x) __builtin_expect((x),1) +#define unlikely(x) __builtin_expect((x),0) + /* Types */ #include <stdint.h> -- 2.35.1

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operator to prepend bgp path multiple times
by Alexander Zubkov 14 Mar '22

14 Mar '22

Hi, I suggest to add a new operator: prepend_times(P, A, N) - that will allow to prepend AS A to path P several times (N). Now we need to use some function like this: function add_prepends(int asn, int num) { if num = 1 then { bgp_path.prepend(asn); } else if num = 2 then { bgp_path.prepend(asn); bgp_path.prepend(asn); } else if num = 3 then { ... } Usually the number of prepends is observable, so this function can fit most of cases, but with available operator it will be a bit more convenient, a little syntactic sugar. But it is not something that is hard to live without, of course. In my patch, I chose to "join" implementations of prepend() and prepend_times(). It is questionable, because it requires some additional supporting stuff if I understood right. So may be it is better to implement it as separate operators.

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constant for empty prefix set
by Alexander Zubkov 14 Mar '22

14 Mar '22

Hi, I propose to add some constant for empty prefix set, for example (as in the patch): define pfx_empty = [ /empty/ ]; It is useful when we define a named prefix list, which we can use somewhere in filters, but this prefix list is generated, for example, and we may need to make it empty. But there is no currently means to create an empty prefix set, as I understand.

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FreeBSD, multiple routing tables, "KRT: Error sending route 192.222.249.232/29 to kernel: File exists"
by Dan Mahoney 13 Mar '22

13 Mar '22

Hey there, We've got a fairly simple setup where we have two fibs. Interface routes are in both fibs the way BSD does it. (Table 1 is the second fib, if it matters). log syslog all; protocol kernel { scan time 20; ipv4 { import all; export all; table master4; }; kernel table 1; } protocol kernel { ipv6 { import all; export all; table master6; }; kernel table 1; } protocol device { scan time 10; } setfib 1 netstat -nr: Routing tables (fib: 1) Internet: Destination Gateway Flags Netif Expire default 192.222.249.233 UGS bge0 127.0.0.1 link#5 UH lo0 127.0.0.2 link#6 UH lo1 192.222.249.232/29 link#1 U bge0 fib 0 would be the same. An old thread seemed to imply this was because the "direct" protocol was missing. Adding the "direct" protocol doesn't stop this error every 20 seconds in syslog (which seems to be related to the scan time). Mar 12 15:24:11 box1 bird[34463]: KRT: Error sending route 192.222.249.232/29 to kernel: File exists Mar 12 15:24:31 box1 bird[34463]: KRT: Error sending route 192.222.249.232/29 to kernel: File exists Mar 12 15:24:51 box1 bird[34463]: KRT: Error sending route 192.222.249.232/29 to kernel: File exists Mar 12 15:25:11 box1 bird[34463]: KRT: Error sending route 192.222.249.232/29 to kernel: File exists Mar 12 15:25:31 box1 bird[34463]: KRT: Error sending route 192.222.249.232/29 to kernel: File exists Is it possible bird isn't differentiating routes learned from each fib and is learning from both, separately, and not properly deduplicating those routes? -Dan

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birdc configure exits with 0 on error
by Vincent Bernat 11 Mar '22

11 Mar '22

Hey! "birdc configure" (or any command in fact) exits with 0 on error. This is a bit annoying as when using "systemctl reload bird", we get no notification there is an error. Looking at the source code, it seems there is no easy way to hack around that. Commands do not report an error code and messages printed are not tagged as errors. Here is a small workaround for systemd: -- Keep it simple to make it faster. - The Elements of Programming Style (Kernighan & Plauger)

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Can pagination be disabled on the Bird console?
by Adrian Brooks 11 Mar '22

11 Mar '22

Hello, Is it possible to configure the Bird console so that the output isn't interrupted with '-More-' statements please? (similar to the Cisco 'terminal length 0' command) I'm using Expect in a Python script to collect data from Bird, so it would be handy to be able to switch this off (I'm using 2.0.9) Many thanks for your time, Adrian Adrian BROOKS Telecom Networks - Fixed Services Platforms Tel. : +352 2424 2301 adrian.brooks(a)post.lu<mailto:adrian.brooks@post.lu> POST Technologies 20, Rue de Reims L-2417 Luxembourg www.posttechnologies.lu<http://www.posttechnologies.lu/> [logo_technologies(a)2x.png] Ce message et toutes les pièces jointes (ci-après le "message") sont établis à l'intention exclusive de ses destinataires et sont confidentiels. Si vous recevez ce message par erreur, merci de le détruire et d'en avertir immédiatement l'expéditeur. Toute utilisation de ce message non conforme à sa destination, toute diffusion ou toute publication, totale ou partielle, est interdite, sauf autorisation expresse. Internet ne permettant pas d'assurer l'intégrité de ce message, POST Luxembourg décline toute responsabilité au titre de ce message, dans l'hypothèse où il aurait été modifié.

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Re: comparing open source BGP stacks performance
by Justin Pietsch 04 Mar '22

04 Mar '22

(added bird-users@ back, I didn't mean to remove them before) Sorry that I missed that you'd already added the pull request. I merged it. we do need a way to specify exabgp vs bird, but that's just another thing to add. I agree about containers and versions. Just haven't had time to think it through carefully. The policy support is what bgperf had before I forked it. I don't use it, I don't know how to usefully test with it. One more feature I'd like to see, yet I'm not sure how to do this > properly – to make the measurement more accurate, the target should not > only run on its own machine, but bgperf with all the testers should also > watch their load, issuing warning when the bgperf suite may be the > bottleneck. This will probably help testing some hardware routers in a > somehow comparable way. > I agree. My best quick hack for this is to make sure that there are extra resources on the CPU when running. That's why bgperf now tracks %idle. As you can probably tell, bgperf isn't a great architecture now, and I'm trying to get useful results as quickly as possible. So much could be done here. thanks a lot! Justin On Tue, Aug 31, 2021 at 2:30 AM Maria Matejka <maria.matejka(a)nic.cz> wrote: > Hello! > > On 8/31/21 1:29 AM, Justin Pietsch wrote: > > I meant to ask if you'd compared exabgp to bird as testers? I'll try to > > compare later if I have some time. > Well, I have no exact numbers, I just implemented the bird tester and it > seems to eat less memory and less time. You could probably run the same > batch first with exabgp testers and then with bird testers, comparing > how much this affects the results. > > > On Mon, Aug 30, 2021 at 4:27 PM Justin Pietsch <jpietsch(a)gmail.com > > <mailto:jpietsch@gmail.com>> wrote: > > > > This is fantastic!!!! Can you submit those changes as PRs to my > > bgperf? I'm working on moving it to a more permanent place. Then we > > can track issues! :) > > Well, yes, the tester exchange is already there pending: > > https://github.com/jopietsch/bgperf/pull/1 > > and it seems that there are two more from somebody else. > > The tester exchange is anyway quite stupid and may need some similar > code to MRT testers instead of what is there now. > > > your suggestion for specifying branches used to work in bgperf, but > > I broke it in trying to get everything working. I moved some of the > > targets to just download prebuilt docker images, which makes it > > harder. Also with batch I'm not sure how to have multiple versions > > of the same container. Just more things to figure out, but that all > > makes sense. > > I think it would be better to have separate containers for different > branches, yet I couldn't figure out how to do that, except for brutal > solutions which were too disgusting to implement. > > Anyway, when BIRD is used as tester, it shouldn't imho change with the > target, which is probably the main reason why I prefer separate > containers for branches. > > One more thing – when running update -c, the container should also pull, > not only checkout, imho. (Haven't had time to fix this yet.) > > > * fixed policy configuration in BIRD (no clue whether it works > with > > other stacks) > > This may need thorough examination first to formally define what the > policies should mean. It would be really stupid to compare route > filtering with different policies in each stack. > > One more feature I'd like to see, yet I'm not sure how to do this > properly – to make the measurement more accurate, the target should not > only run on its own machine, but bgperf with all the testers should also > watch their load, issuing warning when the bgperf suite may be the > bottleneck. This will probably help testing some hardware routers in a > somehow comparable way. > > Maria >

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Bird BFD is not compliant to RFC5881
by Christian Bruns 02 Mar '22

02 Mar '22

Hi all, we experienced issues with non-functional BFD Sessions. Debugging yielded that bird does not use RFC compliant BFD Port ranges. RFC 5881 states: "" The source port MUST be in the range 49152 through 65535. ""; however, the port range is not restricted within bird and thus using arbitrary high ports. Some tier 1 transit providers like "Deutsche Telekom" apply strict filter for BFD and only allow RFC5881 compliant ports, hence the issue. There is a workaround to limit the port range globally at system level (/proc/sys/net/ipv4/ip_local_port_range); this seems to work, but we have the strong feeling that restriction of port range for BFD sessions should happen within bird itself. Kind regards, Christian

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Understanding BIRD log messages
by Jon Langemak 01 Mar '22

01 Mar '22

Im trying to make sure I understand the log messages Im seeing during BGP convergence events. Was hoping someone could validate what the following messages meant... added - A route was received from the peer listed and added to the RIB added [best] - A route was received from the peer listed and added to the RIB and is now the best option in the RIB removed - A route originally received from the peer listed was removed removed [replaced] - Im not clear on what this one actually means ignored - A route was received from the peer listed but ignored. Does ignored in this case mean that it wasn't put in the RIB? If so - does that imply that it was filtered? Is there a list of what all these log messages mean? Also - I assume that the < and > signify direction - that is received or sent but clarification on that would be good as well. Thanks!

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