Re: [SLUG] Internet Gateway/Router

[Malcolm V <farkit@xxxxxxxxxxxx>]

Terry Denovan wrote:

> Hi SLUG,
>
> I am wanting to know if its possible to setup a Linux Box that will 
> allow me to connect 4 ADSL Connections to my Internal Network, and use 
> only 1 internal gateway. I have attached a basic diagram on what I 
> would like to achieve, As you will see from diagram, I have used false 
> IP’s. Essentially, what I would like to do is have the following ports 
> from the internal network go…
>
> SMTP (25) – eth1
>
> FTP (21) eth2
>
> HTTP (80) eth3
>
> VPN (5000) eth4
>
> And similar if you are on the internet,
>
> I want to open port 25 (SMTP) on all the internet connections and have 
> that forwarded to one Internal IP Address, and open port 80 (http) on 
> eth3, and open port 5000 (VPN) on eth4.
>
> eth2 is purely for Staff to use FTP in or Out.
>
> So Basically, the questions are
>
>    1. Is it possible?
>    2. If Possible, What software should I be using? And is it hard?
>    3. If it’s hard, can someone out there do it, and I pay you for it?
Yes, it is possible.

It does however sound like QOS (with a little iptables help) on a single 
connection may be more appropriate. With quality of service you can 
ensure certain protocols get a specified share of the available 
bandwidth and also ensure that any "spare" bandwidth is also available 
to be used by anyone who needs it. Your suggested setup could see the 
"eth4" modem choked by vpn connections whilst the other three 
connections sit idle.

Cheers,
Malcolm V.