Subject: [apps-discuss] APPSDIR review of draft-ietf-6renum-enterprise-04

From: S Moonesamy <[email-masked]>
Date: Mon, 10 Dec 2012 11:08:20 -0800

I have been selected as the Applications Area Directorate reviewer 
for this draft (for background on APPSDIR, please see 
http://trac.tools.ietf.org/area/app/trac/wiki/ApplicationsAreaDirectorate ).

Please resolve these comments along with any other Last Call comments 
you may receive. Please wait for direction from your document 
shepherd or AD before posting a new version of the draft.

Document: draft-ietf-6renum-enterprise-04
Title: IPv6 Enterprise Network Renumbering Scenarios and Guidelines
Reviewer: S. Moonesamy
Review Date: December 10, 2012
IETF Last Call Date: November 28, 2012
IESG Telechat Date: December 13, 2012

Summary: This document is almost ready for publication as an Informational RFC.

The document focuses on enterprise network renumbering.  Most of the 
analysis is also applicable to ISP network renumbering.  The impact 
on applications is the reconfiguration of application services when a 
network is renumbered.  There isn't any discussion of the application 
services angle in the document.

Major Issues:

After reading the document several times I was left with a sense that 
there is an unclear picture.  The preparations for renumbering seem 
to be mainly about DNS and identifying long-lived sessions.  I rate 
this review as poor as I found it difficult to grasp how Section 4 
fits in with the rest of the document.

Figure 1 in Section 2 has an "APP server".  Section 4.1 mentions that:

   "Manual-configured addresses are not scalable in medium to large
    sites, hence are out of scope.  Manually-configured addresses/hosts
    should be avoided as much as possible."

I understand that manual configuration of addresses is not 
scalable.  There is a discussion which may be relevant for 
application servers in draft-ietf-6renum-static-problem.  I suggest 
adding some text to clarify the APP server angle.

Minor Issues:

In Section 4.1:

    "In general, Fully-Qualified Domain Names (FQDNs) are recommended
     to be used to configure network connectivity, such as tunnels,
     servers etc. The capability to use FQDNs as endpoint names has
     been standardized in several RFCs, such as [RFC5996], although
     many system/network administrators do not realize that it is there
     and works well as a way to avoid manual modification during
     renumbering."

The usage of FQDNs is only useful to identify endpoint 
names.  Application servers are generally assigned static IP 
addresses.  Manual configuration of application services is sometimes 
needed during renumbering.  There are possible issues when an 
application service relies on DNS (e.g. 
http://httpd.apache.org/docs/2.2/dns-caveats.html ).

Nits:

In Section 3.1:

   "The enterprise network switches to a new ISP. When this occurs,
    the enterprise stop numbering its resources form the prefix"

There is a typo for "from".

Regards,
S. Moonesamy