Linux system as a router

Linux system as a router

[Kirkwood, David A.]

How do I set up iptables to make the linux system function as a router?
I think I need to set forwarding between the two interfaces, but I don't
understand the syntax of the command.

Thanks,

David A. Kirkwood

Re: Linux system as a router

[Uwe Kiewel]

Kirkwood, David A. wrote:
> How do I set up iptables to make the linux system function as a router?
> I think I need to set forwarding between the two interfaces, but I don't
> understand the syntax of the command.

echo "1" > /proc/sys/net/ipv4/ip_forward

Maybe you will need masqerading

HTH,
	Uwe

Re: Linux system as a router

[Richard Nairn]

If you are doing NATting at the router you need a rule such as 
iptables -t nat -I POSTROUTING -o eth0 -j MASQ if you have a dynamic address, or
iptables -t nat -I POSTROUTING -o eth0 -j SNAT --to-source 1.2.3.4 if you have a static address

you also need net.ipv4.ip_forward=1 in /etc/sysctl.conf

Then have your default route go out your WAN interface.

On Tue, 07 Apr 2009 14:13:18 -0600, Kirkwood, David A. <DAVID.A.KIRKWOOD@saic.com> wrote:

> How do I set up iptables to make the linux system function as a router?
> I think I need to set forwarding between the two interfaces, but I don't
> understand the syntax of the command.
>
> Thanks,
>
> David A. Kirkwood
>
>
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