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From: chris@GYRE.UMD.EDU (Chris Torek)
Newsgroups: mod.protocols.tcp-ip
Subject: Re:  Avalanche
Message-ID: <8605312211.AA03618@gyre.umd.edu>
Date: Sat, 31-May-86 18:11:40 EDT
Article-I.D.: gyre.8605312211.AA03618
Posted: Sat May 31 18:11:40 1986
Date-Received: Sun, 1-Jun-86 05:35:22 EDT
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Approved: tcp-ip@sri-nic.arpa

Indeed, it seems to me that IP forwarding should default to `off'
on most Unix machines.  It also makes sense to disable it if the
machine has only one IP interface; this is what 4.3 does.

For anyone who has not already done it, IP forwarding may be
turned off as follows:

	1) binary-only:
	   The first write turns it off in the running kernel; the
	   second turns it off in the boot image.
		% su
		[password]
		# adb -w /vmunix /dev/kmem
		ipforwarding/W 0
		ipforwarding:	1 =	0
		ipforwarding?W 0
		ipforwarding:	1 =	0
		[type ^D here]

	2) source:
	   Find the declaration of `ipforwarding' in
	   /sys/netinet/ip_input.c; change it to be initialised to zero.

Chris