Subject: [mpls] Benoit Claise's No Objection on draft-ietf-mpls-entropy-lsp-ping-04: (with COMMENT)

From: "Benoit Claise" <[email-masked]>
Date: Wed, 31 Aug 2016 08:33:14 -0700

Benoit Claise has entered the following ballot position for
draft-ietf-mpls-entropy-lsp-ping-04: No Objection

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COMMENT:
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As noted by Scott Bradner in his OPS DIR review, 2 issues worth
addressing IMO.

I did an OPS-DIR review of Label Switched Path (LSP) and Pseudowire (PW)
Ping/Trace over
 MPLS Network using Entropy Labels (EL)
(draft-ietf-mpls-entropy-lsp-ping-04)

The draft extends the existing MPLS LSP Ping and Traceroute multipath
mechanisms to
 support LSPs that use an Entropy Label.

The primary operational impact of this technology is to provide an
additional tool for network
 operators to debug their networks - a good thing.

I found the draft a bit hard to follow, it seems to be more a collection
of data points than a
 clear narrative but I do not think it is worth a rewrite to make it
easier to understand.

I found one thing that raises an operational concern - the next to last
paragraph in 
section 2 says: “All LSRs along the LSP need to be able to understand the
new flags 
and the new multipath information type.” But I do not see a mechanism
discussed to check to 
see if that is the case  (like the high order two bits of IPv6 options). 
If there is a 
mechanism it might be good to describe it, if there is not, a statement
that 
verifying this condition is outside of the scope of the draft would be
helpful

The same paragraph goes on to say  “It is also required that the
initiating 
LSR can select both the IP destination address and label to use when 
transmitting MPLS echo request packets.” It might be helpful to say under

what conditions this is or is not the case.

Otherwise, the draft seems ready for publication.