> My concern with using the unspecified address comes from the > experience we had in MAGMA where we had to specify which source > address to use in the MLDv1 packets.
RFC 3590 does allow the unspecified source for MLD messages during DAD, so the parallel for RS works quite fine. > Further, some might want to > perform some kind of filtering based on the link-local source address, > and using the unspecified address makes this impossible. What type of filtering do you have in mind? What problem would such filtering solve? > I mentioned only because DHCP assigned addresses are probably > indistinguishable (depends on where they sit) from the manual > addresses, but depending on the deployment, I guess DHCP could be > giving the EUI64 addresses as well. Is this an implementation concern i.e. that the code which decides whether to do optimistic DAD might not know whether the address was assigned by the DHCP client or manually by an administrator? That implementation concern is easy to handle; I even know an implementation which sets IFF_DHCPRUNNING for the addresses that are managed by the dhcp client. > Are you sure DHCP servers check that no duplicates are given? Am I sure that the IEEE and the vendors don't hand out duplicate blocks/adresses? No - life is full of different probabilities. > Another potential scenario might be that the DHCP server is > reconfigured (one node removed, another added with the same address), > but the removed node still keeps its address and the new node will be > on the same link.. But such a DHCP server doesn't work well with laptops which might be temporarily disconnected while the DAD occurs. Thus a good DHCP server would retain state about its leases in stable storage to minimize the risk of crashes or reconfiguration resulting in handing out duplicate addresses. Erik -------------------------------------------------------------------- IETF IPv6 working group mailing list [EMAIL PROTECTED] Administrative Requests: https://www1.ietf.org/mailman/listinfo/ipv6 --------------------------------------------------------------------
