RE: NOTE: WG Last Call: draft-ietf-v6ops-mech-v2-01.txt

[itojun@itojun.org (Jun-ichiro itojun Hagino)]

> The current text is ambiguous as to whether it would be legal or
> illegal for the mobile node to (say) use a larger MTU on interface 2 
> (with IPv4 DF bit clear) automatically upon being configured to be a 
> mobile node.  Is the intent that this is illegal?  If so, this 
> seems harmful, and it would be good to point out that excessive 
> fragmentation will occur for mobile nodes.  If this is not the 
> intent, then the language should be clarified.
> 
> Also on the sentence:
> > A larger fixed MTU should not be configured unless it has
> > been administratively ensured that the decapsulator can reassemble
> > packets of that size.
> 
> RFC 2460 section 5 says:
> >  A node must be able to accept a fragmented packet that, after
> >  reassembly, is as large as 1500 octets.
> 
> Is this statement sufficient "administrative assurance" that the 
> decapsulator can reassemble packets up to 1500 octets in size?
> 
> If so, I'd propose rewording as:
> > A fixed MTU larger than 1500 bytes should not be configured unless it
> has
> > been administratively ensured that the decapsulator can reassemble
> > packets of that size.

	the above sentence encourages unmatched/unnegotiated MTU/MRU
	configuration.  i saw problems with these in the past so i'm skeptical
	with the suggested change.

itojun