Sharing a Connection using Linux

hi,
i am new to the world of networking (and Linux, somewhat)

i have a dsl connection that i want to share w/ roommates.
i was thinking of using a linux box with a set of NICs to give each
roommate a line.

I am not sure if i shoudl use that designated box as a
1. proxy server
2. use of masqarading (NAT)
3. if i should just buy a router from office max for $75

what are the pros and cons, or maybe i should ask why would i use any of
the above options?

Yanal wrote:

> i have a dsl connection that i want to share w/ roommates.
> i was thinking of using a linux box with a set of NICs to give each
> roommate a line.

If you don't want to do really weird stuff, you'll probably want a linux box
with two NICs (one for the LAN, one for Internet connection).

> I am not sure if i shoudl use that designated box as a
> 1. proxy server

I wouldn't recommend this. A SOCKS server is a security risk if it is
misconfigured.

> 2. use of masqarading (NAT)

This is probably the best choice.

> 3. if i should just buy a router from office max for $75

....though this is probably easier to set up.

> what are the pros and cons, or maybe i should ask why would i use any of
> the above options?

A (SOCKS) proxy server can only be used with applications which support
SOCKS proxies. Besides, as I mentioned above, it is a security risk (an open
SOCKS server is a gold-lined invitation card for the proxy-raping spammers).

The fundamental difference between 2 and 3 is configurability. $75 routers
aren't all that configurable, whereas a Linux box can do anything a $3000
router would. OTOH, a simple router is simple to configure and very hard to
break permanently, whereas a Linux router may not be all that easy to
configure. And believe me, a Linux box is also all too easy to reduce to the
FUBAR state.

There are some good guides for setting up a linux router. I'd start with
Rusty's Fairly Unreliable Guides:
<http://www.netfilter.org/documentation/index.html#HOWTO>. I used Netfilter
and NAT howto to set up a router at work, and it works perfectly (that is,
it works perfectly only when our SDSL provider feels like providing any
service).

HTH,

-Timo

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Yanal <(E-Mail Removed)> wrote:
....
> i have a dsl connection that i want to share w/ roommates.
> i was thinking of using a linux box with a set of NICs to give each
> roommate a line.

I'd go for two NICs in the Linux box and a switch for the LAN
connections.

> I am not sure if i shoudl use that designated box as a
> 1. proxy server

To speed up internet connections, I'd recommend running squid
(www.squid-cache.org) as proxy.

> 2. use of masquerading (NAT)

There is a masquerading HOWTO (www.tldp.org), squid does proxy
http/ftp, for instant messaging and alike you need masquerading.

> 3. if i should just buy a router from office max for $75

The easiest way.

> what are the pros and cons, or maybe i should ask why would i use any of
> the above options?

A Linux router does offer you features like traffic shaping, a state-full
firewall and more. You won't get with some cheapo hw router only with
$$ Cisco equipment.

On the other hand it will require more work to get it running, albeit
there are some single floppy disk router for Linux.

--
Michael Heiming

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