RFC on solution to Rejean's situation

[Luke Davis]

On Sat, 1 Nov 2003, Allan Shaw wrote:

> 1: I don't by the need or justification for 2 modems either from a
> bandwidth or data transfer requirement.  The cable modem alone is more than
> likely sufficient to meet and exceed the network requirements.

I made the same comment, and posed the question, more than once.  The last
time was earlier today, and after a long discussion, he has convinced me
of its value.
There are port blocking issues with the ADSL provider, and bandwidth
issues with the cable.  Apparently, the cable connection simply does not
have the bandwidth to carry the necessary traffic.

Now, if this were me, I would obtain either a 720K SDSL connection, or a
fractional T1, and be done with it all, but it's not me, and not my
finances.  As far as I can see, he is doing it in the only way possible to
do it currently, without changing the amounts of money spent on
connections drastically.

As such, I am going to try to assist the situation as-is, with the
understanding that I can't change the internet access situation.  So I
either accept it and help, or don't accept it, and not help at all.  I
choose the former solution.

> 2: If you have 2 routers with 2 networks the 2 networks should be joined
> through the routers not having a system bridging the networks.

Clarify this a bit...

Are you saying that the two internal Windows networks should become one,
absorbing the Linux box?  If so, I completely agree.  My solution, while
granted of the sledge-hammer sort, does accomplish this.

If you're talking about "joining" the DSL and cable connections via their
routers, I do not see exactly how you plan to pull that off.  I don't know
what routing technology he has on site.
If he has a good one, with four or so ports, he could probably plug both
modems into this, and essentially do what I was suggesting, in a piece of
hardware.  The question then is: what about the firewalling?

> 3: Instead of trying to fix this problem with a sludge hammer, go out and
> get the right equipment, namely a new Firewall/router with a 8 port switch
> and connect all servers and workstations to this device, a single modem and
> then configure it to allow and direct the appropriate services to the
> appropriate server/workstation.

There will not be a single modem.  There has to be two as things stand,
and if a solution does not take this into account, it is not a solution.

> 4: Personal opinion, I have rarely seen such a convaluded network
> configuration in nearly 20 years of working with networks, but this is only
> my opinion.

You mean my suggestion, or the existing setup?
When I first came to this, I had never seen anything like the original
setup--two connected Windows networks, two separate access points, two
subnets, all connected, in a very odd balance.  I'm trying to simplify
that, by getting everything on to a single subnet, for starters.

Note, that the projects involving using old PCs as routers, using the
power of Linux's iptables configurability, is cheap routing technology, is
becoming quite common.  You seem to suggest (maybe I read you wrong), that
doing this, regardless of the application I suggest, is, to expand upon a
letter, stupid.
I disagree with that, if indeed it is what you are saying.
Now, my application of the method may not be good, which is my entire
point in bringing it here, but the use of dedicated routing boxes in place
of hardware routers, is not new, and is highly tested.

Luke