Subject: Re: ACCEPT [LL17] "directly routed"?

From: Stuart Cheshire <[email-masked]>
Date: Tue, 18 Feb 2003 16:30:53 -0800

Erik Guttman proposed the following terminology definition:

    directly routed

       A datagram is directly routed to a destination if it is sent
       to the destination address.  A datagram that is directly
       routed MUST NOT be sent to another address so that it will
       be forwarded to the destination address.

I think the first sentence says nothing.

I also think that the term "directly routed" is self-contradictory. The 
concept of "routing" means "going through routers". The concept of 
sending a packet "directly" to its destination means "NOT going through 
routers".

Perhaps the term should be "directly delivered" or "delivered directly".

We should reserve the term "routed" for its commonly understood meaning, 
namely, "pertaining to routers".

Stuart Cheshire <[email-masked]>
 * Wizard Without Portfolio, Apple Computer, Inc.
 * www.stuartcheshire.org

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From: Erik Guttman <[email-masked]>
Date: Thu, 20 Feb 2003 17:05:59 +0100 (CET)

> Perhaps the term should be "directly delivered" or "delivered directly".

Actually, I think what we are trying to get at is if you want to send to
destination D you should send directly to D, not to some other address
not-D so as to get the packet delivered to D.  

There are many reasons you might send to not-D to get to D - such as
"going through routers,"  tunneling, knowing somehow that the host with
an interface configured with address D also has another (or the same)
interface configured with address not-D.  In each case, we do not want
to allow these routing behaviors (forwarding, encapsulating, accessing
of an 'adjacent' interface).

I fully agree the wording of the definition needs work.

Erik