> Also now it seems to me that even the current code is not valid as it > implicitly assumes that the prefix length is 128 with this flag. > As the spec says 'low-order 8 octets of the advertised prefix' then > if one advertise 2001:DB8:1020:3040:5060:7080::/96, then low-order > 8 octets of this *prefix* are 1020:3040:5060:7080 and not > 5060:7080:0000:0000.
Right. The spec is imprecise here -- what is meant is the address advertised within the update TLV, after compression. So a router can advertise 2001:db8:1020:3040:5060:7080:dead:beef/96 which advertises 2001:db8:1020:3040:5060:7080::/96 and sets the router-id to 50:60:70:80:de:ad:be:ef. > It seems that when used outside of the scope of obvious application (full > IPv6 address), this flag is not really well specified (and does not make > much sense). Agreed, compression is underspecified in quite a few ways. Mea culpa. -- Juliusz
