--- venaas@xxxxxxxxxxx wrote:
>
> but a single
> packet should not go to more that one receiver.
This is the optimal case - however, I don't recollect reading any rfc
that says that this is guaranteed in a ip network. In practice, this
should not happen unless something's broken.
> If for
> instance there are two routers on a link and a host on the link sends a
> packet to the subnet-router anycast address, how should one decide which
> one to respond
I would expect the packet to get delivered to the MAC address of one of
the routers - which of course is unique to each router interface. Which
one depends on the outcome of race conditions.
>
>
> Yes. What should be limited though is global usage, since it increases the
> size of the global routing tables.
yes, there was quite a bit of discussion at the BoF about this. If anycast
uses unicast space, then aggregation could follow normal unicast aggregation
policies, but perhaps at the expense of less optimal routing of anycast.
There was also a draft from someone at MIT suggesting seperate allocation
of "anycast address space" - you may find the draft if you search internet
drafts for "anycast".
cheers,
karthik
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