On Tue, 2003-08-19 at 13:53, David S. Miller wrote: > BTW, this ARP source address algorithm we use comes from > ipv6, it would be instructive to go and see why they do > things the way they do. Are you sure? See below: ======================================================================== RFC 2461 Neighbor Discovery for IPv6 December 1998 4.3. Neighbor Solicitation Message Format Nodes send Neighbor Solicitations to request the link-layer address of a target node while also providing their own link-layer address to the target. Neighbor Solicitations are multicast when the node needs to resolve an address and unicast when the node seeks to verify the reachability of a neighbor. 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Type | Code | Checksum | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Reserved | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | | + + | | + Target Address + | | + + | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Options ... +-+-+-+-+-+-+-+-+-+-+-+- IP Fields: Source Address Either an address assigned to the interface from which this message is sent or (if Duplicate Address Detection is in progress [ADDRCONF]) the unspecified address. Destination Address Either the solicited-node multicast address corresponding to the target address, or the target address. Hop Limit 255 Authentication Header If a Security Association for the IP Authentication Header exists between the sender and the destination address, then the sender SHOULD include this header. Narten, et. al. Standards Track [Page 21] ======================================================================== Regards, // Steve - : send the line "unsubscribe linux-net" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html