Hi,



I have reviewed this document as part of the Operational directorate's 


ongoing effort to review all IETF documents being processed by the IESG. 


 These comments were written with the intent of improving the 


operational aspects of the IETF drafts. Comments that are not addressed 


in last call may be included in AD reviews during the IESG review. 


Document editors and WG chairs should treat these comments just like any 


other last call comments.




This document is on the Standards Track to deprecate the RFC 4008 MIB
mobule NAT-MIB. At the same time the document obsoletes the RFC 4008.

While I am not a MIB expert this document does not really require any
MIB expertise. However, since there were modifications to the existing


MIB I also ran the MIB against an automated MIB tester tool. The 


smilint reports the following warnings:






* mibs/NAT-MIB:15: [5] {import-unused} warning: identifier 


`DisplayString' imported from module `SNMPv2-TC' is never used


* mibs/NAT-MIB:27: [5] {import-unused} warning: identifier 


`InterfaceIndex' imported from module `IF-MIB' is never used


* mibs/NAT-MIB:33: [5] {import-unused} warning: identifier 


`InetAddressPrefixLength' imported from module `INET-ADDRESS-MIB' is 


never used


* mibs/NAT-MIB:36: [5] {import-unused} warning: identifier `VPNIdOrZero' 


imported from module `VPN-TC-STD-MIB' is never used




Comments:

* If the intention is to obsolete RFC4008 NAT-MIB _why_ this document
  then does additional changes to the MIB than just marking objects
  deprecated? This concerns 1) added imports and 2) changed contact
  information and possible other places as well (I did not make a
  full diff).

* Unused Reference: 'RFC4787' is defined, but no reference was found
  in the text.

* SNMP acronym is the first time used in Section 1 unexpaned. The
  acronym is expanded later in Section 2. Expand it already in
  Section 1.

* While the Security Considerations is good information and a clear
  upgrade to RFC 4008 one, I wonder why that has to be different than
  in RFC 4008, which is now being deprecated by this document?

* The Security Considerations does not really discuss the security
  implications of the _deprecation_ itself e.g. there is going to be
  boxes out there that use the old MIB and others that use the new
  (to be approved) MIB and what that mixed environment might entail.
  There is some text that is getting to that direction (SNMPv2 and
  SNMPv3 security differences).

* There is also no text about operational and management implications
  related to deprecation process of the old MIB and migrating to the
  new (to be approved) NAT-MIB-v2).

* Since the new MIB is kind of requirement for replacing this old
  to be deprecated MIB, I would assume the draft-ietf-behave-nat-mib-v2
  to be a _normative_ reference in this document.

- Jouni