Community for small IX - problem with 4B ASN

Piotr Marciniak zboj at mnc.pl
Tue Jan 23 17:02:20 CET 2018


Thank you - I don't think we will need aliases for 4B ASn, but if we do - 
yest, it is nice example.

Thank you again,

Piotr Marciniak

-----Oryginalna wiadomość----- 
From: Vasily Oleynikov
Sent: Tuesday, January 23, 2018 10:36 AM
To: Piotr Marciniak ; bird-users at network.cz
Subject: Re: Community for small IX - problem with 4B ASN

Hello

I'm using some dirty trick for this
(It's example for some peer. Configs is generating automatically, so
template is the same for all peers, changes only currentas variable)


filter Peer_export
     int currentas;
     int myas;
     {
     currentas = 20000;
     myas = 50000;
     if (currentas = 123456) then
         {
         currentas = 65502;
         }
     if (currentas = 123457) then
         {
         currentas = 65504;
         }
     if (currentas = 123458) then
         {
         currentas = 65501;
         }

     if ( (1,currentas) ~ bgp_community ) then
         {
         bgp_path.prepend(bgp_path.first);
         }
     if ( (2,currentas) ~ bgp_community ) then
         {
         bgp_path.prepend(bgp_path.first);
         bgp_path.prepend(bgp_path.first);
         }
     if ( (3,currentas) ~ bgp_community ) then
         {
         bgp_path.prepend(bgp_path.first);
         bgp_path.prepend(bgp_path.first);
         bgp_path.prepend(bgp_path.first);
         }
     if (0, currentas) ~ bgp_community then reject;
     if (currentas,myas) ~ bgp_community then accept;
     if (59712,5000) ~ bgp_community then accept;
     if (0, myas) ~ bgp_community then reject;
     }

And my peers using 655xx AS in community for prefix control.
I'm understanding that it's not the best and most elegant solution, but
it works.


22.01.2018 15:15, Piotr Marciniak пишет:
> Hello,
>
> I've spent a while on below docs and faced a problem with 4B ASN we use.
> Bird reports an error 'when 'myas' is 4B => so above 65535.
> See some testing example below:
>
> bird> configure
> Reading configuration from /etc/bird/bird.conf
> /etc/bird/bird.conf, line 81: Value 165250 out of range (0-65535)
>
> The only way this config reports no error is to set here private ASn - fe. 
> 65250. But it will never match our real ASn.
>
> Two questions:
>
> 1. Is it possible to enable 4B ASn for communities in Bird? Will it work 
> with other rouers?
> 2. Can we use instead private ASn just for community filters? Are they 
> processed corretly by other Internet routers of our peers?
>
> Or maybe there is another work around?
>
> Best wishes,
>
> Peter
>
>
> -----Oryginalna wiadomość----- From: Piotr Marciniak
> Sent: Friday, December 29, 2017 5:01 PM
> To: Ondrej Zajicek
> Cc: bird-users at network.cz
> Subject: Re: Community for small IX
>
>
> There are some examples in BIRD wiki, mainly:
>
> https://gitlab.labs.nic.cz/labs/bird/wikis/Route_server_with_community_based_filtering_and_multiple_RIBs
> https://gitlab.labs.nic.cz/labs/bird/wikis/Route_server_with_community_based_filtering_and_single_RIB
> 



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