Re: IKEv2 Correction (editorial)

[Paul Koning <pkoning@equallogic.com>]

>>>>> "Radia" == Radia Perlman <- Boston Center for Networking <Radia.Perlman@Sun.COM>> writes:

 Radia> I don't understand why reserved fields shouldn't be "MUST be
 Radia> sent as zero". At least for implementations of this
 Radia> draft. There might be a future version that uses the bits, but
 Radia> that spec would no longer say "MUST be sent as zero". Instead
 Radia> it would say "MUST be set to the grobnitz filter value" or
 Radia> whatever the reserved bits get used for.

 Radia> If the spec for this version of IKE says SHOULD, doesn't that
 Radia> allow a vendor to use the bits for some proprietary purpose?

Two reasons.

1. "SHOULD" on send rules is the standard rule.
2. If you say "MUST send as zero" that creates a strong temptation in
   receivers to check for zero and reject the packet if a non-zero is
   found.  If that is done, the whole version thing breaks.

	   paul