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North American Network Operators Group Date Prev | Date Next | Date Index | Thread Index | Author Index | Historical BGP filtering of supernets out of classful space
In attempting to help someone with regards to BGP announcement filtering from the IRR we've found the following situation: A provider in China has been assigned addresses in the traditional class C space. APNIC's assignment is a /16 for this allocation. Said provider, trying to be good Internet citizens are announcing only aggregates of /16. However, they're running into several providers that are filtering the announcements because they aren't /24. Experimentation has proven that announcing /24's will solve this problem. This obviously clutters up the global routing tables. The primary justification I can see for such filtering is to prevent "sink routing" - or catching everything else where more specific routes don't exist. (This would probably be a Bad Thing for the provider foolishly making such announcements - a very effective self DoS attack.) What methodology are providers using for these types of route filtering issues now? (I'll save the IRR pulpit for later.) And yes, I have directed the provider having the routing issues to contact each ISP doing the filtering separately. -- Jeffrey Haas - Merit RSng project - [email protected]
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