- Bird-users - Mailing Lists

[PATCH] protocol aggregation
by Alexander V. Chernikov 03 Apr '17

03 Apr '17

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[Feature request] DHCPv6 protocol
by Martin Huněk 02 Apr '17

02 Apr '17

Hello, When I was recently in CZ.NIC and I've asked for this feature (DHCPv6 protocol support in bird), I've been told that I should try to make my case on this list. So: (Short list on bottom) I think that adding the DHCPv6 would be logical step for bird development due to DHCPv6-PD (prefix delegation). Today, if you want to do DHCPv6-PD on Linux you have these options: 1) Run DHCPv6 relay on L3 switch / router (on segment) and DHCPv6 server on Linux: Then you can run any of current servers (ISC DHCP, Kea, so on) without problem because routing of the delegated prefix is done on switch/router. It works out of the box and larger ISPs do that. 2) Run DHCPv6 server as stand-alone on Linux: Then you run into problems. None of the current implementation which I've tried (ISC, Kea, DHCPKit) doesn't add routes for delegated prefixes into routing table. This way the delegated prefix is unreachable and end user has got broken connectivity. There are ways how to try circumvent that: a) There is modified version of ISC DHCP which adds information about next hop to hooks. But it is not in mainline. b) You can make hook into standard ISC to guess the link-local address of CPE from DUID. But this might work only for first type of DUID-LLT or third type DUID-LL and only if such DUID is computed from WAN MAC and if it uses EUI-64. c) Snooping of DHCP communication with clients and adjust routing table accordingly. But this depend on another daemon and if it fails, it results in broken connectivity for end user. d) Make static route for every prefix like: 2001:db8:1234:100::/56 via 2001:db8:1234::100 But this makes those prefixes reachable even when not allocated. Making connection to host in such prefix would result in timeout, rather then ICMP message "unreachable". That would not be really DHCPv6-PD because the prefix would be routed to CPE even if it doesn't ask for it. e) Write your own DHCPv6 relay or plug-in to DHCPv6 server (like intended in DHCPKit from RIPE 73) f) Don't use DHCPv6-PD and use static configuration instead. My point is that, there is none of implementation of DHCPv6 server/relay which handles routing of delegated prefix by design. Even there are some ways how to solve that they don't work in all cases (rising amount of devices which uses DUID-UUID or which doesn't use EUI-64 even for link-local addresses). Rather then try to teach DHCPv6 server routing it seems logical to try to teach the routing daemon to dispatch addresses it already have. For a start it doesn't have to be anything fancy, even just relay functionality would have been huge help. Of course the full implementation would have its benefits. Short list of reasons: - No reliable implementation of DHCPv6-PD with routing on Linux - Competitive advantage over Quagga (especially in small networks) - Makes sense to routing daemon to handle routing of a delegated prefix - Less software needed on router just ip6tables and bird for whole IPv6 - Just one software which edits the routing table I do realize that you do have got a lot of work on Bird v2 and that main focus of bird is in BGP, but this feature could really help us as well as other small networks. Best Regards Martin Hunek

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Re: [Feature request] DHCPv6 protocol
by Martin Huněk 02 Apr '17

02 Apr '17

Hi, No argument there, the DHCP server should do that when doing PD but for some reasons they don't. I guess that because of large ISP would use DHCP relay agent in some device, they would not need that. That's why DHCPKit doesn't have that (author doesn't need that, but you are free to do it yourself). I guess that there is also some religious view that the DHCP server should not make routing decisions. It was true before PD, but no one seems to notice that. There is one fork of ISC DHCP (https://github.com/mpalmer/isc-dhcp) which at least gives address of CPE to be available to custom hooks which then allows you to make hook for adding/removing routes for delegated prefixes. However it seems to be dead since end of 2014. I'm not arguing about that it would not be easier to program it into DHCP server, it would be, I'm stating that it would be helpful to have at least relay in bird. Because to have a functional DHCPv6-PD it is necessary to do both routing and DHCP itself and since DHCP servers doesn't do that, routing daemon should. Best Regards Martin Hunek Dne sobota 1. dubna 2017 13:36:40 CEST jste napsal(a): > Hello! > > > Then you run into problems. None of the current implementation which I've > > > > tried (ISC, Kea, DHCPKit) doesn't add routes for delegated prefixes into > > routing table. This way the delegated prefix is unreachable and end user > > has got broken connectivity. > > Maybe I am missing something, but is there any reason for not adding this > feature to the DHCP daemon? It looks much easier than implementing the whole > of DHCP from scratch :-) > > Have a nice fortnight

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Is there a way to speed up config process?
by Lyubomir Millanov 28 Mar '17

28 Mar '17

Hello, I was wondering if there is a way to speed up re-configuration process? Right now it takes up to 30+ minutes to run ./config after modifying bird_config_gen. I'm running BIRD 1.5.0 Best regards, Lyubo

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Transiting
by Michael McConnell 26 Mar '17

26 Mar '17

Hello all, We are running into an issue transiting a down stream ASN. E.g. Uplink <-> Our ASN <-> Downlink ASN To me it seems we should only need to bgp_path.prepend our outbound filter, however our uplink is dropping the as path when we run it that way. Any suggestions as to what I am missing to carrier a downstream ASN and prefixes to our uplinks? Thanks so much, Mike -- Michael McConnell WINK Streaming; email: michael(a)winkstreaming.com <mailto:michael@winkstreaming.com> phone: +1 312 281-5433 x 7400 cell: +506 8706-2389 skype: wink-michael web: http://winkstreaming.com <http://winkstreaming.com/>

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BGP Community Filter Static Route
by Michael McConnell 25 Mar '17

25 Mar '17

Trying to run a bgp filter like so; if (net = 10.10.10.10/24 || (641111, 666) ~ bgp_community ) then { route 10.10.10.10/24 reject; } Of course I run into a syntax error as I can’t inject the static route there. Any suggestions as to how I export a route based on a bgp community string? e.g. if community set export route. Thanks so much, Mike -- Michael McConnell WINK Streaming; email: michael(a)winkstreaming.com <mailto:michael@winkstreaming.com> phone: +1 312 281-5433 x 7400 cell: +506 8706-2389 skype: wink-michael web: http://winkstreaming.com <http://winkstreaming.com/>

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Sending only default route to downstream users?
by Michael McConnell 24 Mar '17

24 Mar '17

Hello all, I receive a full iBGP table from my uplinks, however I want to just pass a default route / partial table to my downstream clients. I’ve tried various options such as gateway direct and multihop, try to turn it into a eBGP situation with no luck. Can anyone point me in the right direction? Thank you very much for your time and help, Mike -- Michael McConnell WINK Streaming; email: michael(a)winkstreaming.com <mailto:michael@winkstreaming.com> phone: +1 312 281-5433 x 7400 cell: +506 8706-2389 skype: wink-michael web: http://winkstreaming.com <http://winkstreaming.com/>

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State of OSPF/ECMP Multipath on FreeBSD
by chrono 24 Mar '17

24 Mar '17

Ahoy all, I've been asking on IRC and tried to find a definitive answer in the ML archives, but I'm still not sure what the current state is. Our Setup: BIRD (1.4.0 FreeBSD 10.x) <- OSPF/MPLS -> BIRD (1.5.0 FreeBSD 11.x) There were some msgs back in 2014 about merging ECMP support for FreeBSD but when I enable it, no more traffic is going through. I can see the Multipath setup in birdc though. Some users on IRC suggested it would only work on Linux but in this case I'm not free to decide which OS to pick and bound to FreeBSD. Did I miss anything or is there really no working ECMP support for bird on FreeBSD yet? If not, is there some sort of bounty possibility? I could check with my company if they're open to it (since we really need it) - if that could help bring that feature forward. -- chrono

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Bird BGP session sending default route
by Michael McConnell 24 Mar '17

24 Mar '17

Hello all, Currently I receive a full route table from our uplinks on our primary routers using BGP, however I am trying to have a downstream bird router / BGP session where I only pass this downstream bird session a default route / partial table. I’ve experimented with the multihop parameters as that is the way I would effectively force a eBGP session in Cisco but not having luck transferring that to bird. Any suggestions how I can create a eBGP session so that I basically only receive a default route instead of the full route table? Thanks so much for your help, I really appreciate it! Mike -- Michael McConnell WINK Streaming; email: michael(a)winkstreaming.com <mailto:michael@winkstreaming.com> phone: +1 312 281-5433 x 7400 cell: +506 8706-2389 skype: wink-michael web: http://winkstreaming.com <http://winkstreaming.com/>

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Filtering question
by Alarig Le Lay 20 Mar '17

20 Mar '17

Hi, I have this configuration: function bgp_filter_customer_in (prefix customer_prefix) { if ! (net ~ customer_prefix) then return false; else return true; } template bgp PEERS { local as myasn; import keep filtered; import all; export all; import limit 100 action restart; rs client; source address 2001:7f8:b1::1; } filter bgp_filter_grifon_nominoe_in { if (bgp_filter_customer_in([ 2a00:5884::/32, 2001:678:3cc::/48 ])) then { accept; } else { reject "Prefix filtered for Grifon"; } } protocol bgp bgp_grifon_nominoe from PEERS { description "Grifon nominoe"; neighbor 2001:7f8:b1::a as 204092; import filter bgp_filter_grifon_nominoe_in; } But the two announced prefixes are filtered: bird> show route filtered protocol bgp_grifon_nominoe 2a00:5884::/32 via 2001:7f8:b1::a on eth2 [bgp_grifon_nominoe 16:05:53] (100) [AS204092i] 2001:678:3cc::/48 via 2001:7f8:b1::a on eth2 [bgp_grifon_nominoe 16:05:53] (100) [AS206155i] If I just pass one prefix in the filter, this prefix is accepted, so I don’t understand why they are filtered with this configuration. Plus, I used the same syntax for the IPv4 prefixes and it works. I’m using bird 1.6.3. Thanks for your advices, -- alarig

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