>>> 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. /~\ The ASCII Mouse \ / Ribbon Campaign X Against HTML [email protected] / \ Email! 7D C8 61 52 5D E7 2D 39 4E F1 31 3E E8 B3 27 4B
