On Thu, Aug 16, 2007 at 10:42:20PM +0200, Aurelien Jarno wrote: > >> Rule 9: Use longest matching prefix. > >> When DA and DB belong to the same address family (both are IPv6 or > >> both are IPv4): If CommonPrefixLen(DA, Source(DA)) > > >> CommonPrefixLen(DB, Source(DB)), then prefer DA. Similarly, if > >> CommonPrefixLen(DA, Source(DA)) < CommonPrefixLen(DB, Source(DB)), > >> then prefer DB. > > > > That's a rule that might work for IPv6, but not for IPv4. But even when > > using IPv6, I think you want the CommonPrefixLen to be atleast 24 bit, > > maybe even 32, or even 64. > > > > So, because I happen to have a 10.0.0.0/8 address, it prefers addresses > > which as many as possible 0's at the front. This is unlikely to give me > > an address that's going to be close network-wise, since none of the > > returned addresses are actually in 10.0.0.0/8. > > The fact you have a 10.0.0.0/8 does not changes anything to the way the > list is sorted in rule 9. Only the returned addresses are taken into > account.
It sorts the list in such a way that the top most bits are the same. So it first sorts by: 10.0.0.0/8 then: 10.0.0.0/7 8.0.0.0/6 8.0.0.0/5 0.0.0.0/4 0.0.0.0/3 0.0.0.0/2 0.0.0.0/1 And then finaly the rest (128.0.0.0/1) The first of those makes sense for me, the rest doesn't. Kurt -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]
