Dave,
So in order to preserve the behavior you are describing, the packet needs to be routed over the RLOC space as early as possible. This corresponds to placing the ITRs deeper in the site (closer to the source hosts). Since the ITR will encapsulate the packet (and the outer header destination address will be a locator), it will find thebest exit just as it does today.What would be the benefit and driver for such large corporate sites to install ITRs ?Finer-grained control over exit policy without having to propagate global state inside your enterprise.
But what you and Tony replied are not the mirror replacement of today's optimal routing to dst prefix ... this is optimal closest exit strategy or in other words ability to find closest ITR. I am not aware about an ITR to ITR relays for optimal routing towards destination in any of the current proposals :).
I wonder why so many networks today still run full BGP inside rather then just injecting whole bunch of even anycast defaults into their IGP to ASBRs. It would be nice to have such public data :).
Perhaps engineers of such networks should speak up on their reasons as I can not disclose neither the names nor their internal network architecture fundamentals ...
Cheers, R. -- to unsubscribe send a message to rrg-request@psg.com with the word 'unsubscribe' in a single line as the message text body. archive: <http://psg.com/lists/rrg/> & ftp://psg.com/pub/lists/rrg