Subject: Re: NetBSD as a bridge/firewall
To: None <firstname.lastname@example.org>
From: Matthias Scheler <email@example.com>
Date: 08/11/2002 08:26:26
In article <firstname.lastname@example.org>,
Kevin Sullivan <email@example.com> writes:
> I'm setting up a firewall for a small business's DSL line. They have a /28
> coming out of the DSL modem. Since there is no place to put a router (and
> they don't want NAT), I'd like to set up a bridge/firewall where a computer
> acts as a ethernet bridge and also filters packets. Can this be done with
> NetBSD 1.6?
NetBSD can't do filtering on a bridge. The only way to handle this
scenario is using proxy arp. Assuming you get 18.104.22.168/16 from your
provider and the NetBSD machines has two interface "fxp0" and "epic0"
your setup could look like this:
fxp0: 22.214.171.124 netmask 255.255.255.240 connected to DSL modem
epic0: 126.96.36.199 netmask 255.255.255.248 connected to LAN
Now use "arpd" from "pkgsrc/net/arpd" to provide proxy arp for 188.8.131.52
to 184.108.40.206 on "fxp0".
Matthias Scheler http://scheler.de/~matthias/