Subject: [lisp] #87: On reusing globally routed address block as EID-prefix (comment 11 reported by Y. Rekhter)

From: "lisp issue tracker" <[email-masked]>
Date: Wed, 28 Apr 2010 04:53:38 -0000

#87: On reusing globally routed address block as EID-prefix (comment 11 reported
by Y. Rekhter)
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Reporter:  wmhaddad@…          |       Owner:                 
    Type:  technical           |      Status:  new            
Priority:  major               |   Component:  draft-ietf-lisp
Severity:  -                   |    Keywords:                 
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 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 ?

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Ticket URL: <http://trac.tools.ietf.org/wg/lisp/trac/ticket/87>
lisp <http://tools.ietf.org/lisp/>
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