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: santi...@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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