Can somebody draw me a picture? [Emphasis on the word "useful."]Brian,
Attached, please find a rough-cut and incomplete picture. It depicts two administrative domains (A and B), each with a node that is engaged in a peer-to-peer session (a.com and b.com). Domain A uses a native IPv6 prefix space and has delegated a portion of the space to a (b)router upstream from the node "a.com". Domain B uses a 6to4 prefix space and has delegated portions of the space to a hierarchically nested pair of (b)routers upstream from node "b.com".
If the DNS entries for 'a.com' and 'b.com' are populated with AAAA resource records as shown in the picture, one could view the presence of the ISATAP-format link local addresses as an unambiguous indication that the nodes "support the protocol", and could use the ISATAP link-local address as the IPv6 next-hop toward the final destination.
The picture shows a stream of packets emanating from a.com towards b.com (and, similarly, for packets emanating from b.com towards a.com). These outbound packets would be encapsulated using ISATAP and it would appear from IPv6's perspective that they are being "bridged" up to the edge of the remote peer's domain (although there would still need to be some flavor of NDproxy in operation). Once the inbound packets hit the edge of the remote peer's domain, the packets would be decapsulated and steered towards the final destination within the domain via the delegated IPv6 prefix information.
The question comes when we consider the inbound packets arriving at the edge of administrative domain B. Does the edge node use 6to4 or ISATAP to decapsulate the packets. (And, does it even matter?)
Fred ftemplin@iprg.nokia.com
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6to4tap.ppt
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