Le 12 août 2010 à 21:47, Alain Durand a écrit : > I have a question about draft-ietf-6man-node-req-bis-05.txt. > Section 5.2: > > Redirect functionality SHOULD be supported. If the node is a router, > Redirect functionality MUST be supported. > > However, draft-ietf-6man-node-req-bis-05.txt refer to the normative text on > Neighbor Discovery, ie RFC4861 that says: > Section 8.2: > > > A router SHOULD send a redirect message, subject to rate limiting, > whenever it forwards a packet that is not explicitly addressed to > itself (i.e., a packet that is not source routed through the router) > in which: > > - the Source Address field of the packet identifies a neighbor, > and > > - the router determines (by means outside the scope of this > specification) that a better first-hop node resides on the same > link as the sending node for the Destination Address of the > packet being forwarded, and > > - the Destination Address of the packet is not a multicast > address.
In my understanding, this says that a router that has no means to ever find a better next hop never needs to send a redirect message. An simple unmanaged home gateway, for example, may therefore not need to support any redirect-message transmission. It may still have to process redirect messages received at its wan interface (at least if this interface is neither to a P2P link nor to a virtual link a la 6to4), but would not need a complete redirect functionality. One approach in draft-ietf-6man-node-req-bis-05 could then be: "Redirect functionality SHOULD be supported, subject to conditions set forth in section 8.2 of RFC 4861." Regards, RD > > It seems that the Node requirement text is going above and beyond what is > required by RFC4861, transforming the SHOULD into a MUST. > I might have missed (or do not remember) the discussion, is there a reason > for this change? And shouldn't the ND spec have been changed first > to allow to upgrade the SHOULD into A MUST? > > For the record, I support the SHOULD in RFC4861 and I would rather like to > see the node requirements document say the same thing. > > - Alain. > > -------------------------------------------------------------------- > IETF IPv6 working group mailing list > ipv6@ietf.org > Administrative Requests: https://www.ietf.org/mailman/listinfo/ipv6 > -------------------------------------------------------------------- -------------------------------------------------------------------- IETF IPv6 working group mailing list ipv6@ietf.org Administrative Requests: https://www.ietf.org/mailman/listinfo/ipv6 --------------------------------------------------------------------
