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I raised a few on the INT-AREA mailing list in Oct 2005 in the
pre-ICMP/MPLS split which were not addressed in either the 00 or 01
versions of this draft.

- ---
Use of the "unused" area, as Ron suggested, seems inappropriate because
those fields are not known to be 'cleared' by existing ICMP sources, so
their value cannot be reliably used for flags IMO.
- ---

A few further concerns are below:

The technique of using a valid checksum to "correctly determine" that
the option is present at the 137th byte is overstated. The 1's
complement checksum can be used to infer that data has not been
corrupted, but it is not appropriate for data synchronization (the use
here), as would, e.g., a stronger sum such as a CRC. 1's complement is
known to be susceptible to packet corruption that dovetails portions of
packets together (see Stone and Partridge, Sigcomm 2000).

Finally, and most importantly, the document does not sufficiently
address how it will affect the payload of ICMP packets, in changing
existing Internet recommendations. When the payload of certain messages
is smaller than 128 bytes, it will work fine. However, section 6
suggests (somewhat obscurely) that future implementations send only 128
bytes to represent the datagram. This is in direct opposition to the
recommendations of RFC 1812.

The only solution to these issues appears to be the creation of new type
codes and the emission of two errors for each ICMP error - one under the
current code, one with the new, augumented code. Short of this, it is
unclear that a backward compatible extension such as this can usefully
coexist.

Joe

Ron Bonica wrote:
> None that have been brought to my attention.
> 
>                             -ron
> 
> Margaret Wasserman wrote:
> 
>>Thanks, Ron!
>>
>>Are there any remaining concerns about this document that should be resolved
>>before I agree to sponsor it for publication (which will include sending it
>>for a 4-week IETF LC)?
>>
>>Margaret 
>>
>>
>>
>>>-----Original Message-----
>>>From: [EMAIL PROTECTED] 
>>>[mailto:[EMAIL PROTECTED] On Behalf Of Ron Bonica
>>>Sent: Monday, January 30, 2006 9:40 AM
>>>To: [EMAIL PROTECTED]
>>>Subject: [Int-area] draft-bonica-internet-icmp
>>>
>>>Folks,
>>>
>>>I have updated draft-bonica-internet-icmp. The new version 
>>>can be found at the following URL:
>>>
>>>http://www.ietf.org/internet-drafts/draft-bonica-internet-icmp-01.txt
>>>
>>>The most significant change is that the "length" field has 
>>>been moved to avoid a conflict with the "Next-Hop MTU" field 
>>>that is defined in RFC 1191.
>>>
>>>                             Ron
>>>
>>>_______________________________________________
>>>Int-area mailing list
>>>[email protected]
>>>https://www1.ietf.org/mailman/listinfo/int-area
>>>
>>
>>
> 
> _______________________________________________
> Int-area mailing list
> [email protected]
> https://www1.ietf.org/mailman/listinfo/int-area
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