Last Call Review of draft-ietf-6man-ug-05
review-ietf-6man-ug-05-opsdir-lc-bonica-2013-11-28-00

Folks,

The following is an OPS-DIR review of draft-ietf-6man-ug.

SUMMARY: The draft points out a real problem in RFC 4291 and corrects the
problem. I encourage the OPS AD's to ballot YES.

Details: RFC 4291 says:

"For all unicast addresses, except those that start with the binary
 value 000, Interface IDs are required to be 64 bits long and to be
 constructed in Modified EUI-64 format."

As a consequence, the bits 6 and 7 of the IID (known as the u and g bits) are
understood as described in IEEE802. Subsequent to the publication of RFC 4271,
the IETF has published many documents in which the IID is not constructed in
Modified EUI-64 format. Therefore, the u and g bits are relatively meaningless.

draft-ietf-6man-ug corrects the problem by modifying RFC 4271 as follows:

OLD>
"For all unicast addresses, except those that start with the binary
    value 000, Interface IDs are required to be 64 bits long and to be
    constructed in Modified EUI-64 format."
<OLD
NEW>
   "For all unicast addresses, except those that start with the binary
    value 000, Interface IDs are required to be 64 bits long. If derived
    from an IEEE MAC-layer address, they must be constructed in Modified
    EUI-64 format."
<NEW

And

OLD>
"The use of the universal/local bit in the Modified EUI-64 format
 identifier is to allow development of future technology that can take
advantage of interface identifiers with universal scope."
<OLD
NEW>
<NEW

NITS: Please consider the following changes:

OLD>
   IPv6 unicast addresses consist of a prefix followed by an Interface
   Identifier (IID).  The IID is supposed to be unique on the links
   reached by routing to that prefix, giving an IPv6 address that is
   unique within the applicable scope (link local or global).  According
   to the IPv6 addressing architecture [RFC4291], when a 64-bit IPv6
   unicast IID is formed on the basis of an IEEE EUI-64 address, usually
   itself expanded from a 48-bit MAC address, a particular format must
   be used:
<OLD
NEW>
   IPv6 unicast addresses consist of a prefix followed by an Interface
   Identifier (IID).  The IID is unique on the links
   reached by routing to that prefix, giving an IPv6 address that is
   unique within the applicable scope (link local or global).  According
   to the IPv6 addressing architecture [RFC4291], when a 64-bit IPv6
   unicast IID is formed on the basis of an IEEE EUI-64 address, usually
   itself expanded from a 48-bit MAC address, a particular format must
   be used:
<NEW

--------------------------
Ron Bonica
vcard:       www.bonica.org/ron/ronbonica.vcf