Re: LL32 Multihoming

> From: "Robert Elz" <[email protected]>
>
>   | 1. This new addition contradicts existing text elsewhere in the
document,
>   | such as the section I quoted, where interfaces are not treated
>   | independently.
>
> No it doesn't.   Running the algorithm independently means just that,
> it doesn't change what the algorithm is, and if that means checking all
> MAC addresses, then that's part of it (part of each independent execution
> of the algorithm).
>

   "At any time, if a host receives an ARP packet (request *or*
   reply) where the 'sender IP address' is the host's own IP
   address, but the 'sender hardware address' does not match
   any of the host's own interface addresses, then this is a
   conflicting ARP packet, indicating an address collision."

The use of "any" implies that two interfaces on the same host and connected
to the same link would not recognise each others ARPs as conflicts. This is
not independence. Whether this is resolved in other (internal) ways or
causes trouble is very much implementation dependent.

The use of "host's own IP address" is also ambiguous when the host plainly
has multiple IP addresses. For independence, each interface-IP address pair
needs to be treated independently.

It is already clear that LL addressing will not work on multiple interfaces
on the same host unless traffic is closely coupled with specific interfaces
in ways which common APIs have tried to avoid. This is another manifestation
of that effect.

Philip