Subject: Re: scope-exceeded and routing headers

From: [email-masked]
Date: Wed, 26 Jan 2000 15:58:29 -0500

My take on this, without consulting with Steve is:

the  /destination uncreachable/scope-exceded/  error condiftion si detected
on the packet forwarding path, i.e. main header source/destination address
processing.  This implies that there is no difference  between a packet
that has a routing header and one that does not.

Regards,
Alex

Richard Draves <[email-masked]> on 01/26/2000 02:19:02 PM

Sent by:  Richard Draves <[email-masked]>

To:   IPng List <[email-masked]>
cc:    (Alex Conta/US/3Com)
Subject:  scope-exceeded and routing headers

The ICMPv6 draft defines a new destination unreachable code point for
scope-exceeded errors, when forwarding a packet would cause it to leave the
scope of the source address.
Does this same error situation apply to routing header processing?
It seems like allowing a routing header to carry a packet beyond the
source's scope might be useful in some situations, and if the sender is
going to the trouble of specifying a routing header then presumably they
know what they are doing. On the other hand, this could easily violate
assumptions that receivers make about the source address in packets they
receive. (Like being able to reply without using a reversed routing header,
or pseudo-security assumptions.)
Thanks,
Rich
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From: Jim Bound <[email-masked]>
Date: Wed, 26 Jan 2000 22:15:06 -0500

>that has a routing header and one that does not.

Exactly.  This is why it is black and white decision.  Not gray.
The condition test to forward has nothing to do with why or how the
packet got there, but that the packet if forwarded will exceed its
scope. I can't see reading it any other way as an implementor.

/jim

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From: Francis Dupont <[email-masked]>
Date: Thu, 27 Jan 2000 22:34:37 +0100

=> I agree as an implementor too!

[email-masked]