Subject: [apps-discuss] APPSDIR review of draft-ietf-l2vpn-arp-mediation-19

From: S Moonesamy <[email-masked]>
Date: Wed, 02 May 2012 03:23:53 -0700

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-l2vpn-arp-mediation-19
Title: ARP Mediation for IP Interworking of Layer 2 VPN
Reviewer: S. Moonesamy
Review Date: May 2, 2012
IETF Last Call Date: April 12, 2012

Summary: I'll abstain from making any recommendation about 
publication as the L2VPN Working Group has been working on this draft 
since October 2004.

This draft describes methods for ARP Mediation when different 
resolution protocols are used on either Attachment Circuit.  It does 
not contain any Application considerations.  I am not familiar with 
the subject.

Major issues:

It is not clear throughout the document whether "IP address" refers 
to IPv4 and IPv6 or IPv4 only.

In Section 1:

   "In this document, we specify the procedures for VPWS services,
    which the PEs MUST implement in order to mediate the IP address
    resolution mechanism."

BTW, VPWS is expanded on first use below that.

It's difficult to figure out the procedures for that "MUST".

In Section 4.1.2:

   "This document mandates that there MUST be only one CE per
    Attachment Circuit. However, customer facing access topologies
    may exist whereby more than one CE appears to be connected to
    the PE on a single Attachment Circuit."

There is a requirement for only one CE per Attachment Circuit and yet 
it is mentioned that there may be cases where more than one CE 
appears to be connected.  If there are cases when the requirement 
cannot be followed, why is it a requirement?

In Section 8.1:

   "For greater security the LDP connection between two trusted PEs
    MUST be secured by each PE verifying the incoming connection
    against the configured address of the peer and authenticating
    the LDP messages using MD5 authentication, as described in
    section 2.9 of [RFC5036]."

Isn't the MD5 authentication considered as obsolete?

In Appendix A.1:

   "In an IP L2 interworking L2VPN, when an IGP on a CE connected to
    a broadcast link is cross-connected with an IGP on a CE
    connected to a point-to-point link, there are routing protocol
    related issues that MUST be addressed."

Addressing protocol related issues is a vague requirement.

Minor isues:

In Section 2:

   "1. Discover the IP address of the locally attached CE device"

Is this for IPv4 addresses only?

In Section 3:

   "If the IP packet arrives at the ingress PE with multiple data
    link headers (for example in the case of bridged Ethernet PDU
    on an ATM Attachment Circuit), all data link headers MUST be
    removed from the IP packet before transmission over the PW."

What is "PW"?

Nits:

I found the Abstract Section difficult to parse.

There are four authors listed on the first page of the 
draft.  However, there are 16 authors/editors listed in the Authors' 
Addresses section.  Given that there is an IPR disclosure on this 
draft, can the document shepherd answer the following question:

    Has each author confirmed that any and all appropriate IPR
    disclosures required for full conformance with the provisions of
    BCP 78 and BCP 79 have already been filed.  If not, explain why.

Please note that this review does not contain editorial comments.

Regards,
S. Moonesamy

---

From: Stewart Bryant <[email-masked]>
Date: Tue, 15 May 2012 17:13:49 +0100

RFC Editor: please continue with the publication process.

AA Reviewer: thank you for the review

The purpose of the last call was to address an IPR issue discovered
whilst the document was with the RFC Editor, however we
will attempt to address these points.

On 02/05/2012 11:23, S Moonesamy wrote:
> I have been selected as the Applications Area Directorate reviewer for 
> this draft (for background on AppsDir, please see 
> you may receive. Please wait for direction from your document shepherd 
> or AD before posting a new version of the draft.
>
> Summary: I'll abstain from making any recommendation about publication 
> as the L2VPN Working Group has been working on this draft since 
> October 2004.
>
> It is not clear throughout the document whether "IP address" refers to 
> IPv4 and IPv6 or IPv4 only.

SB> I would like to ask the authors to clearly inspect the usage the 
term "IP Address"
and determine whether there is any ambiguity of the term in each case 
and provide
the necessary clarification if required.
> BTW, VPWS is expanded on first use below that.
SB> I am sure the RFC Editor will get that one
> It's difficult to figure out the procedures for that "MUST".
SB> Yes, suggest s/MUST/need to/
> it is mentioned that there may be cases where more than one CE appears 
> to be connected.  If there are cases when the requirement cannot be 
> followed, why is it a requirement?

SB> I suggest:
OLD
This document mandates that there MUST be only one CE per Attachment 
Circuit.
NEW
The method described in  this document only supports the case where 
there is a single CE per Attachment Circuit.
END
> Isn't the MD5 authentication considered as obsolete?
SB> A good point, but this document is not the place to specify LDP 
security.
I suggest the following change:

OLD
NEW
    the LDP messages as described in  section 2.9 of [RFC5036]."
END

> Addressing protocol related issues is a vague requirement.
SB> I think these are addressed in the sub sections that follow.
> Is this for IPv4 addresses only?
SB> IPv6 is described separately in the next para.
>    removed from the IP packet before transmission over the PW."
SB> s/PW/pseudowire/
> I found the Abstract Section difficult to parse.
I think I am OK with it, but will leave it to the RFCEditor to work though
any issues with the Authors.
>
> There are four authors listed on the first page of the draft.  
> However, there are 16 authors/editors listed in the Authors' Addresses 
> section.  Given that there is an IPR disclosure on this draft, can the 
> document shepherd answer the following question:
>

This document was approved by the IESG prior to this procedure coming 
into operation.
The document has been re Last Called on this. It is difficult for any of 
the remaining
authors to justify sitting on IPR.

Stewart

---

From: S Moonesamy <[email-masked]>
Date: Tue, 15 May 2012 10:48:51 -0700

Hi Stewart,
>will attempt to address these points.

I'll say for the record that the comments were addressed.

Regards,
S. Moonesamy