On 19 Dec 2008, at 04:43, 정치영 wrote:
It seems so simple. Currently annoucement of /24 seems to be okey, most upstream providers accept this. However I wonder if there is any ground rule based on any standard or official recommandation.
The only rule is "my network, my rules" ;-) But if general rules did exist, they might say 1) not to announce smaller than a /24 to external parties without agreement, and 2) not to carve up registry assigned address blocks into individual announcements. 1 - You might announce your registry assigned block, AND deaggregated blocks to upstreams or peers for traffic engineering purposes, but you need to work closely with them to make sure that they don't filter the deaggs from your session, and also to make sure they don't onwardly announce the deaggs). 2 - The default free routing table is 270,000 entries large, and this is too big for lots of kit, so networks ARE FILTERING TODAY on registry boundaries. If you don't understand the implications of this do not deaggregate the addresses that the registry assign you. Good luck with your project. Drop me a note offlist if you need specific advice. Andy