Any IX willing to share their config?

Ondrej Zajicek santiago at crfreenet.org
Sat Dec 25 11:57:04 CET 2010


On Sat, Dec 25, 2010 at 05:03:46AM +0200, Alexander Shikoff wrote:
> > One possible way to do that is not to try handle full 32bit ASNs, but
> > perhaps just ~ 24bit ASNs and use communities (65000..65255,*) for
> > "(65000+X,Y) - Do not announce to peer X*65536+Y" and similarly
> > communities (65256..65511,*) for: "(65256+X,Y) - Announce to peer
> > X*65536+Y only".
> You're right.
> If I remember correctly IANA currently allocates 1024 numbers for each
> RIR, so your variant covers them entirely for some future years.
> Some additional thoughts:
> - this way breaks RFC1997 a little
> - current draft "Internet Exchange Route Server" (http://tools.ietf.org/html/draft-jasinska-ix-bgp-route-server-01)
>   does not propose in details how to implement handling of 32bit ASNs
>   via communities. 
> - there is RFC5668 (4-Octet AS Specific BGP Extended Community, 
>   http://tools.ietf.org/search/rfc5668) but it defines only 2 octets
>   for Local Administrator field. So BGP Ext. community support
>   will not also allow easy implementation of 32bit ASN handling.
> 
> I've googled around this problem and have not find yet another 
> ideas/discussions etc. So your way seems to be most easy and effective
> at present moment. 

Another, even simpler, way is to assign each connected client with
32bit ASN some pseudo-ASN from private range. This pseudo-ASN
would be used with standard communities (0:X, MyASN:X).

> RFC1997 community 'no-export' is also supported. Other communities
> including RFC1997 well-known ones are not supported and stripped.

That seems a bit strange to me. Not sure what the other IXPs do but
i think that communities are supposed to be propagated and RS
should alter only communities destined for it.

> ------------------- Communities sent to peers ----------------------
> MyASN:X - Route is received from 16-bit ASN X
> 6550X:Y - Route is received from 32-bit ASN 65535*X+Y
> --------------------------------------------------------------------

What purpose have these communities? That can be easily read from AS_PATH.

-- 
Elen sila lumenn' omentielvo

Ondrej 'SanTiago' Zajicek (email: santiago at crfreenet.org)
OpenPGP encrypted e-mails preferred (KeyID 0x11DEADC3, wwwkeys.pgp.net)
"To err is human -- to blame it on a computer is even more so."
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