>This _might_ be a bug in "TWO_HOURS" rule, see >addrconf.c:addrconf_prefix_rcv. Also see RFC2462 5.5.3. e). (this has >been updated slightly by so-called "Jim Bound rule" afterwards) "jim bound rule" is not an official one. KAME has been using jim bound rule, however, is now using RFC2462. itojun