IPv6 Anycast

So I understand the concept behind the Anycast feature of IPv6. But what I am
failing to understand is the "anycast" option when configuring the ipv6
address.

I assume it is so that the router is aware that the assigned address is an
Anycast address, but I fail to understand why the router needs to know that.
I have read the documentation from Cisco Doc CD and all it says is:

"Assigning a unicast address to more than one interface makes a unicast
address an anycast address. Nodes to which the anycast address is assigned
must be explicitly configured to recognize that the address is an anycast
address."

Can anybody help me understand why the address must be recognized as an
Anycast?

Thanks,

Nathan Richie

Blogs and organic groups at http://www.ccie.net
Received on Fri Oct 09 2009 - 11:34:42 ART