On Tue 24 Aug 2010 at 11:10:55 -0400, der Mouse wrote: > >>> I believe that non-contiguous netmasks actually are illegal nowadays. > >> Cite? > > RFC 4632 (CIDR Address Strategy), section 5.1: > > ...which is titled "Rules for Route Advertisement". (Also, 4632 is a > BCP, not a standard.) > > > " An implementation following these rules should also be generalized, > > so that an arbitrary network number and mask are accepted for all > > routing destinations. The only outstanding constraint is that the > > mask must be left contiguous." > > With respect to route aggregation in advertisements (ie, > exterally-visible behaviour). See the second paragraph of 5.2.
Also (thinking perversely), this never says that the 1-bits in the mask must be left-justified... a mask of 00111111 11111111 11000000 00000000 has the whole mask contiguous... > /~\ The ASCII Mouse -Olaf. -- ___ Olaf 'Rhialto' Seibert -- There's no point being grown-up if you \X/ rhialto/at/xs4all.nl -- can't be childish sometimes. -The 4th Doctor