Document: draft-ietf-pim-group-rp-mapping-07.txt
Reviewer: Brian Carpenter
Review Date: 2010-12-18
IETF LC End Date: 2010-12-23
IESG Telechat date: 

Summary: In good shape, a few issues.
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Major issues:
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3.  Existing algorithm
...
   The algorithm defined in this document updates algorithm defined in
   PIM-SM ( Section 4.7.1 in [RFC4601]).  The new algorithm is backward
   compatible and will produce the same result only if the Group-to-RP
   mappings are learned from a single mapping source.

A logical implication of the last sentence is that if some of the Group-to-RP
mappings are learned from more than one mapping source, the new algorithm
might 
not produce the same result as the existing algorithm. Is that indeed the
case,
and if so, don't we have a problem until all PIM-SM routers have been updated?

5.  Common use cases

   o  Default static Group-to-RP mappings with dynamically learned
      entries

   Many network operators will have a dedicated infrastructure for the
   standard multicast group range (224/4) and so might be using
   statically configured Group-to-RP mappings for this range.  

Please indicate whether this issue also applies to IPv6.


6.  Proposed algorithm
...
   10.  From the remaining set of Group-to-RP Mappings we will select
        the RP with the highest IP address.  This will serve as a final
        tiebreaker.

Please define "highest". Does it mean "greatest when considered as an
unsigned integer"?

8.  Clarification for MIB Objects

   When a Group-to-RP mapping entry is created in the
   pimGroupMappingTable in the PIM-STD MIB[RFC5060], it would be
   acceptable to have an entry with an RP with address type 'unknown'
   and a PimMode of Dense Mode or SSM.  These entries would represent
   group ranges for Dense mode or SSM.

   Also all the entries which are already included in the SSM Range
   table in the IP Mcast MIB would be copied over to
   pimGroupMappingTable.  They would have a type of configSSM and an RP
   with address type 'unknown' as described above.

Is this section intended to be a normative update of RFC 5060, or is
it just commentary? The phrase "it would be acceptable" almost sounds
like a normative MAY.  

Also, shouldn't it be 'unknown(0)' in the context of the MIB? (This
applies in three places in the draft.)


Nits:
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5.  Common use cases
...
   o  More use cases

   By no means, the above list is complete.  Please drop a mail to
   'authors' if you see any other use case for this.

This seems a bit strange to appear in the final RFC; at the least it needs
rewriting.

The checker says:

== There are 1 instance of lines with multicast IPv4 addresses in the
     document.  If these are generic example addresses, they should be changed
     to use the 233.252.0.x range defined in RFC 5771