Re: ADSL

["alcinababe" <alcinababe@xxxxxxx>]

--- In ukha_d@xxxxxxx, Simon Kennedy <stonewolfsoft@y...> wrote:

> Thanks Chris but the answer is still eluding me. Are
> you saying that an IPCop based firewall + an ADSL
> modem does less than an ADSL router and that I would
> need a router as well as an IPCop firewall?
>
> I was under the impression that
> ADSL Modem + IPCop firewall = ADSL Router
>
> At least that's what they seem to imply here
> http://www.mini-itx.com/projects/ipcop/

Sorry if this is a duplicate posting (more or less) - I sent a reply
more than an hour ago and it's still not appeared in the list :(

Try to think of it in terms of signal, and where that signal goes.  An
adsl modem converts the phone signal into a signal a computer can
understand.  But only one computer.  Your basic adsl connection
consists of a BT phone socket to get the signal, a modem to convert
the signal and a computer (to have fun with!):

BT -> modem -> single computer

But you want to have more than one computer.  So you need a router.  A
router 'routes' the signal to/from several computers to/from the modem
utilising some wizardry (usually NAT) which remembers, for example,
which comptuer asked for which web pages.  Otherwise you'd end up
getting someone else's web pages if two people were surfing at the
same time.  In order to pysically connect more than one computer to a
router you also need a hub (gotta have something to plug the cables into):

BT -> modem -> router -> hub -> lots of computers

But what about those nefarious script kiddies?  You need a firewall.
This usually goes between the modem and the router:

BT -> modem -> firewall -> router -> hub -> lots of
computers.

That's your basic model.  The problem is that a lot of the "adsl
routers" that are sold actually contain two or more parts of the above
model.  IPCop is a software router *and* firewall (the software part
means you've got to have a dedicated PC to run it on).  It's model is:

BT -> modem -> IPCop -> hub -> lots of computers

Some adsl routers have a built in router/firewall/hub (albeit usually
only 4 ports):

BT -> modem -> adsl router -> lots of computers

Some have only the the router and firewall:

BT -> modem -> adsl router -> hub -> lots of computers

If you have an all-in-one wonderbox adsl router which actually
comprises a modem, firewall, router *and* hub, the model is:

BT -> wonder box -> lots of computers

So as you can see it all depends on what's actually pysically built
into the box that's called "adsl router".  Check the description
before you buy.  Opinions vary as to whether it's best to have a
single box doing everything, or separate boxes, or upgradable software
firewalls, or security through obscurity dedicated hardware firewalls,
or...you get the idea!

Hope this makes sense (and gets onto the board this time!)

Alcina