On 9 Nov 2004 02:45:30 -0800,
(E-Mail Removed) (Lee) wrote:
>i have a desktop pc (with xp home) that doesnt yet have broadband
>access. i also have someone in the house who i would like to share the
>broadband access with, but not anything else (files, etc). Is it
>possible to have one broadband line coming in, then have the desktop
>and the laptop able to access the internet at any time (inc at same
>time) without having the laptop access any of my data, or indeed me
>able to see what is on his laptop.
>
>I've had a look on the web for solutions and have been considering
>buying a wireless router and 2 wireless network cards for the pc and
>laptop, but then it seems i have to put the 2 in a network for them to
>be able to share the broadband internet access through the router -
>and this is the bit that worries me.
This is the classic "coffee shop" problem. You build a coffee shop
hot spot for customers to share a single DSL or cable modem. Only one
IP address is delivered by the ISP. How do you keep the customers
from seeing the coffee shop office computers? The same problem
includes users that want to share their connection with the neighbors,
but not expose their computers to the anyone outside the LAN.
This has been discussed before with various solutions. The easiest is
to obtain a 2nd IP address from the ISP. You would use two routers,
one for each "group" of users. Neither LAN would see each other, even
if they had identical IP address blocks. I have 5ea IP addresses from
SBC and use this method to connect 4ea seperate companies on a single
DSL modem.
If you're stuck with a single IP address, you setup the wireless and
internal LAN with different Class C IP blocks. For example, the
wireless router DHCP delivers IP's in 192.168.1.xxx and the internal
LAN runs on 192.168.2.xxx. You don't really need a 2nd router to
connect these two seperate LAN's as you could setup a static route to
the wireless router at 192.168.1.1 from 192.168.2.xxx on every client
machine and point the default route to 192.168.1.1. However, this
creative routeing has proven to be a rather painful exercise in
maintenance, so I add a 2nd router to connect 192.168.1.xxx with
192.168.2.xxx. The static route method isn't terribly secure as a
clueful wireless user could easily break into the internal LAN.
Another method is two routers in series playing double NAT. The
default route for the 2nd router would point to the first router.
Therefore (methinks), the 2nd LAN would not see any machines on the
first LAN.
/----\ /----\
== DSL ====| |======================| |====
Modem | |=== 192.168.0.xxx | |==== 10.0.0.xxx
| |=== | |====
| |=== Office LAN | |==== Coffee Shop
| | | | Network
\----/ \----/
Router #1 Router #2
Wireless 192.168.0.xxx Wireless 10.0.0.xxx
for office LAN for coffee shop
The "right" way is to get a router with multiple LAN side ports. I do
this using FreeSCO:
http://www.freesco.org
routers built around old PC's. To the best of my knowledge, there are
no cheapo wireless routers that offer multiple independent LAN side
ports. So, you build your own. It's not that bad and makes sense in
some situations.
>oh, a side question - does the router stay connected to the internet
>permanently? what happens if the line drops for whatever reason?
That depends on the router. If you have to deal with a login/password
abomination commonly found in PPPoE connections, there's usually a box
labelled something like "keep alive" or "auto-reconnect". Some have a
timeout setting which is suppose to disconnect you after xxx number of
minutes. Setting it to zero disables the timer. Most of the current
models have some method of staying on or logging back in. These are
generally un-necessary as most Windoze clients are so "noisy", that
any packet that needs to access the interknot, will bring up the
connection. Not a problem.
--
Jeff Liebermann
(E-Mail Removed)
150 Felker St #D
http://www.LearnByDestroying.com
Santa Cruz CA 95060 AE6KS 831-336-2558