On Mon, Dec 20, 1999 at 07:10:37PM +0300, kuznet@xxxxxxxxxxxxx wrote:
> > unicast mechanism is different from anycast. Also, there is no
> > need for the receiver to be aware of the fact that it has an
> > anycast address - it could be part of an anycast group without
> > it's knowledge.
> Nope. It's knowledge is the _only_ thing differing anycast of unicasts.
> They are indistingushable outside of receivers.
> I suspect we talk about different things. 8)
My understanding is:
"Classical" anycast addresses are indistuingishable from normal addresses
for both senders and receivers, the trick is the routing. Different
senders may reach different receivers using the same address, but a single
packet should not go to more that one receiver.
RFC 2373 states though that receivers must be configured to know it's an
anycast address. There are AFAIK a lot of open issues here. 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, of course this is a problem in some other scenarios as
> > anything formal yet, there was no intent to prohibit it's use within
> > individual administrative domains either.
> It would be pretty funny, if some IETF meeting prohibited to do something
> within an individual administrative domain 8)8)8)
Yes. What should be limited though is global usage, since it increases the
size of the global routing tables.