On Mon, 2012-07-16 at 23:36 -0700, Owen DeLong wrote:
Reread the spec... [the subnet router anycast address] gets the packet to one or more of the routers and it may well lead to packet duplication. There may or may not be coordination between the routers. It isn't in the spec.
Which spec? Looking at RFC 4291, Section 2.6.1: Packets sent to the Subnet-Router anycast address will be delivered to one router on the subnet. All routers are required to support the Subnet-Router anycast addresses for the subnets to which they have interfaces. The Subnet-Router anycast address is intended to be used for applications where a node needs to communicate with any one of the set of routers. But I do not have an encylopaedic knowledge of all the RFCs, so perhaps this has been superseded, obsoleted or updated... Reading it with a squint: The phrase "packets [...] will be delivered to one router on the subnet" does not specifically exclude the possibility that packets will be delivered to more than one router on the subnet. Still, I do think it would be a little unreasonable to interpret it thus. Regards, K. -- ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Karl Auer (kauer@biplane.com.au) http://www.biplane.com.au/kauer GPG fingerprint: AE1D 4868 6420 AD9A A698 5251 1699 7B78 4EEE 6017 Old fingerprint: DA41 51B1 1481 16E1 F7E2 B2E9 3007 14ED 5736 F687