On reusing globally routed address block as EID-prefix (comment 11 reported by Y. Rekhter)

[wmhaddad@…]

Section 3

A globally routed address block (whether PI or PA) is not
an EID-prefix. However, a globally routed address block may be
removed from global routing and reused as an EID-prefix. A site
that receives an explicitly allocated EID-prefix may not use that
EID-prefix as a globally routed prefix assigned to RLOCs.

The above implies that if an existing site has IPv4 addresses that are used for global connectivity, and thus act as RLOCs, the site can not use these addresses as EIDs, unless the site removes them from global routing, and thus stops using them as RLOCs.

Does the spec assume that IPv4 sites that want to use LISP would need to get another block of IPv4 addresses for the EID prefix ?

If yes, then where would these IPv4 addresses come from ?

If a site that has IPv4 addresses and uses them for global connectivity (these addresses act as RLOCs) wants to transition to LISP, but can not get another block of IPv4 address for the EID-prefix, then how would that site transition to LISP, and what are the implications on that site's connectivity during the transition? E.g., could some,
but not all, of the border routers of the site during the transition be xTRs ? If yes, then how would an ITR attract traffic from a site if the site also has a default route to a non-ITR router ?

Does the EID space need to be aggregatable, as if yes, then how would one accomplish this in the context of IPv4 addresses ?

[luigi@…]

The issue has been fixed in version -12 of the draft as described in section B.1:

• Tracker item 87. Once again reword the definition of the EID-prefix to reflect recent comments.

[yakov@…]

From the most recent text:

A globally routed address

block may be used by its assignee as an EID block. This would
require coordination and cooperation with the entities managing
the mapping infrastructure. Once this has been done, that block
could be removed from the globally routed IP system, if other
suitable transition and access mechanisms are in place.

The last sentence in the above does not clearly identify what kind of transition and access mechanisms need to be deployed in order to remove a globally routed address block from the globally routed IP system.