Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP
Path: utzoo!utgpu!water!watmath!clyde!cbosgd!ihnp4!homxb!mtuxo!mtune!rutgers!husc6!hao!ames!ucbcad!ucbvax!UCBVAX.BERKELEY.EDU!karels%okeeffe
From: karels%okeeffe@UCBVAX.BERKELEY.EDU.UUCP
Newsgroups: comp.protocols.tcp-ip
Subject: Re: On broadcasts, congestion and gong
Message-ID: <8710280106.AA29957@okeeffe.Berkeley.EDU>
Date: Tue, 27-Oct-87 20:06:04 EST
Article-I.D.: okeeffe.8710280106.AA29957
Posted: Tue Oct 27 20:06:04 1987
Date-Received: Sun, 1-Nov-87 06:55:43 EST
Sender: daemon@ucbvax.BERKELEY.EDU
Organization: The ARPA Internet
Lines: 22

Please, check your facts before sending flames to mailing lists!
4.3BSD does NOT do IP forwarding on singly-homed hosts, although
the ipforwarding variable is not cleared.  Only hosts with multiple
hardware interfaces with IP addresses need to be configured consciously
to avoid packet forwarding; such hosts need to be configured carefully
in any case.  4.2's forwarding behavior was different, of course.
Neither decision was random.

The recent comments about escaped broadcast packets had a number
of inaccuracies.  In particular, unrecognized broadcast messages wouldn't
be treated any differently than a host on the same network as the broadcast;
thus, they wouldn't be sent using a default route unless there were no
route to the destination network.  This is very unlikely for a directly-
connected network.  4.2 didn't recognize many current broadcast addresses;
4.3 recognizes most attempts to concoct broadcast addresses on the local
networks.  Of course, broadcasts for nonexistent subnets (or packets for
hosts on nonexistent subnets) are sent using the default route.  That's
one reason that gateway that are advertised as defaults within subnetted
networks should never use default routes themselves.  (However, Kirton's
EGP probably doesn't check for net 0, the "default" net, on input.)

		Mike