Hemant Singh: > Well, did folks get a chance to read this draft which > proposes normative changes to an existing RFC as follows. The text is > snipped from section 6 of draft-kohno... > > > [The [RFC4291]is to be revised to allow longer prefix than /64, and > state that Subnet-router anycast address MUST be disabled if > the prefix > length of the link is /127.] > > I, and I think Dave Thaler too, are saying that the above text is not > acceptable because existing IPv6 RFCs can deal with the situation of > /127 configured and not invoking anycast data forwarding. > Since we said > no RFCs need to change, we had to get into router internals to explain > how so.
On prefix length, RFC 4291 says: "For all unicast addresses, except those that start with the binary value 000, Interface IDs are required to be 64 bits long and to be constructed in Modified EUI-64 format." So, longer than 64-bit prefixes are already possible. Is the objection the restriction that the first three bits must be set to zero for these longer prefixes? As to subnet router anycast, in a /127 subnet, subnet router anycast will always identify one of the two routers, the one with host ID 0. I'm not sure what the issue is with this. RFC 4291 would only need to change if there are problems with these two issues, seems to me. Bert -------------------------------------------------------------------- IETF IPv6 working group mailing list [email protected] Administrative Requests: https://www.ietf.org/mailman/listinfo/ipv6 --------------------------------------------------------------------
