Subject: draft-ietf-ipngwg-addr-arch-v3-07.txt and FF00::/16 and FF0F::/16?

From: Markku Savela <[email-masked]>
Date: Mon, 11 Mar 2002 16:00:32 +0200

The scope value is [0..F], but 0 and F are marked as "reserved".

Usually "reserved" values in protocols can be handled by "ignore on
receive, zero on send".

However, with scope and scoped addressing, I just can't ignore it on
receive. What should I do with addresses starting with

  FF00::/16
  FF0F::/16

a) when receiving a packet using those as destination.

  My first assumption: Drop it

b) when application requests sending a packet to such address?

  My first assumption: reject with error

Above logic will be hardcoded in all stacks, so anyone thinking later
of redefining the meanings is severly limited.

Just wanting to verify that I can do it in above way. Actually, only
the value 0 is the problematic one (for 'F' I can just pretend that it
is just another level above global, like universal :-).

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From: Steve Deering <[email-masked]>
Date: Tue, 12 Mar 2002 15:57:11 -0800

At 4:00 PM +0200 3/11/02, Markku Savela wrote:
>What should I do with addresses starting with
>
>  FF00::/16
>  FF0F::/16

You are correct that the spec is silent on that, and ought to say something.
Given the implied ordering of scope levels, I think the following rules
would be reasonable (basically agreeing with you):

	packets sent to FF*0::/16 should be discarded (silently?) at
	the source and discarded silently if received.

	packets sent to FF*F/16 should be treated the same as global
	multicasts.

Steve