Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP
Path: utzoo!mnetor!uunet!seismo!sundc!pitstop!sun!amdcad!ames!ucbcad!ucbvax!OKEEFFE.BERKELEY.EDU!karels
From: karels@OKEEFFE.BERKELEY.EDU (Mike Karels)
Newsgroups: comp.protocols.tcp-ip
Subject: Re: On broadcasts, congestion and gong
Message-ID: <8711010744.AA08758@okeeffe.Berkeley.EDU>
Date: Sun, 1-Nov-87 02:44:44 EST
Article-I.D.: okeeffe.8711010744.AA08758
Posted: Sun Nov  1 02:44:44 1987
Date-Received: Thu, 5-Nov-87 07:47:05 EST
Sender: daemon@ucbvax.BERKELEY.EDU
Organization: The ARPA Internet
Lines: 32

On RFC-1009 compliance of 4.3: I haven't looked at the RFC nearly
as closely after it was issued as before, and I'm not sure what
changes were made after the last draft.  (Not as many as I would
have liked, I guess; I sent in almost 10 pages of comments on the
last draft.)  However, 4.3 comes fairly close to compliance.  As
a host (esp. singly-homed), it is quite conservative about what it
will respond to, and it won't forward packets.  As a gateway, it
does nearly everything as the RFC specifies, with some minor
exceptions.  For example, it uses both host and net redirects, with
host redirects used for if the route used is for a host or subnet
and net redirects otherwise; the RFC says to use only host redirects.
(Or was that for unreachables?  The opposite conclusion was drawn
for the two.) Nearly all of the IP and ICMP options and types are
supported, with the exceptions of security and TOS (but who knows
what to do with these?).  I should make a pass over the RFC soon;
we plan to release a current copy of the networking code soon
with Van's TCP changes as well as the bug fixes since the first release.

Most things are automatically configured.  John Lekashman mentioned
various options controlling forwarding, gateway function, and generation
of redirects; these are set only for performance reasons (more buffers
and bigger hash tables for gateways) or to cause unusual combinations,
such as machines that forward packets but won't send redirects.
Hosts with one interface won't forward; hosts with multiple interfaces
assume that they are gateways unless ipforwarding is disabled (either
at compile time, or by patching a variable).  Sorry, John, but I have
to disagree that configuring multi-homed hosts is only one line
different in the startup file; multi-homed hosts *have* to be more
carefully configured, if only because some form of routing needs to be
done to choose the correct outgoing interface.

		Mike