Trouble configuring network gateway

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-----Original Message-----
From: owner-freebsd-questions at freebsd.org
[mailto:owner-freebsd-questions at freebsd.org]On Behalf Of John C
Sent: Saturday, April 12, 2003 5:14 PM
To: freebsd-questions at freebsd.org
Subject: Trouble configuring network gateway


Hello,

I am attempting to turn a PC into a gateway/firewall for my home network.
My ISP is Comcast ... So whatever ramifications therein, for better or
worse, apply to my predicament ...

I've gotten both interfaces up and working, but I can't seem to get it to
switch packets from within the subnet out into the internet.  The kernel is
pretty much GENERIC 4.7, except with the GATEWAY option set, plus with

net.link.ether.bridge=1

In sysctl.conf

My configuration is as follows:

Gateway machine: "argonath"
External network interface: sis0 12.235.54.203 (netgear card, ip provided by
DHCP)
Default route: 12.235.54.129 (presumably my cable modem)
Private subnet interface: rl0 192.168.0.1

Secondary subnetted machine "shelob":
Interface 192.168.0.2
Default route: 192.168.0.1

I can ping & ssh to "argonath" from "shelob", and can reach the internet
from argonath's rl0 ... But like I said, the gateway action isn't happening.

One other thing I found odd is that when my secondary machine is plugged
directly into the Comcast subnet, it reports a default route of 12.235.36.1,
which seems more right, but I don't have experience enough in these matters
to say, and what documentation I've found isn't specific enough to give me a
clue about how to solve this problem ...

Please help?

Thanks,
John

You need to set up network address translation. The following section from
the handbook should help you:

http://www.freebsd.org/doc/en_US.ISO8859-1/books/handbook/natd.html

Beech

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