Add ad-hoc internet to LAN?

  • Thread starter Thread starter ironmanc
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ironmanc

I have a Cable modem, into a Speedstream 2601 single port
router/DHCP and a 4 port hub. This will network several
desktop computers, all configured as clients, plugged
into the hub, all getting /ip addresses, etc., from the
router, as MSHOME workgroup. One desktop runs XP (named
XPDesk). The router is actually pretty good, has
optional DHCP and accepts routing and gateway commands.

I would like to add a USB 802.11b wireless client adaptor
to one desktop computer (XPDesk, running XP SP1) and ad-
hoc it to my laptop (named "laptop", also running XP SP1,
with ORiNOCO Silver PCMCIA). The laptop works great on
other networks, etc.

But it's not that simple. I can't set the XPDesk
computer as DHCP, because the router is the DHCP. I can
disable DHCP in the router if needed. My laptop never
gets an address (because the router/dhcp isn't on the
wireless link), so it takes a 169.254.x.x for itself. Of
course, now it doesn't hear the XP desktop.

I can set the XP desktop as host, 192.168.0.1, enable ICS
on ethernet interface(again), and then it works but ONLY
between XPDesk and laptop - no internet access (and
probably not to the other computers???)

If I remove the gateway, plug the cable modem directly
into the desktop, (ICS enabled), then XPDesk and internet
works to the laptop, but I no longer have my wired
LAN,just XPDesk and laptop.

I'm a cheapskate and don't want to use a 2nd ethernet
card, or buy a wireless gateway (I have one in the
shop). But mainly, I want to understand what's going on
here, so when it comes up in the future, I'll know what
to do - and WHY. I also like the extra protection the
router offers, in the way of NATS, firewall, etc.

Here's a diagram of my LAN:

Comp2 Comp3 Laptop w/wireless
| | ~
CaMdm>--Router/DHCP>--4PortHub>--XPDesk>-USB-Wireless

Questions:
1. Who's on DHCP? Router or XPDesk?

2. Please give specific examples of proper /ip addresses
for each machine, including the router & laptop, i.e.
router 192.168.0.x, XPDesk 192.168.0.1 DHCP ICS, etc.

3. Do I need routing command on router for for
router>XPDesk>laptop? And on laptop for
laptop>XPDesk>router? Or just XPDesk as gateway? Or
will this be automagically handled?

4. Does the DHCP server automagically have all default
traffic sent to it? If so, how do I make Comp2 & Comp3
internet traffic go directly to the router, and not via
XPDesk?

5. Anything I missed? Any books, docs, homework, etc., I
should read, do, etc.?? I really want to understand the
process.

Thanks very much in advance. And be assured that I will
share this knowledge with others, as I have for many
years, and hope to for many to come.


-mike curtis
ironmanNOSPAM (at) ironmanDIESPAMDIEcurtis <dot> com
 
ironmanc said:
I have a Cable modem, into a Speedstream 2601 single port
router/DHCP and a 4 port hub. This will network several
desktop computers, all configured as clients, plugged
into the hub, all getting /ip addresses, etc., from the
router, as MSHOME workgroup. One desktop runs XP (named
XPDesk). The router is actually pretty good, has
optional DHCP and accepts routing and gateway commands.

I would like to add a USB 802.11b wireless client adaptor
to one desktop computer (XPDesk, running XP SP1) and ad-
hoc it to my laptop (named "laptop", also running XP SP1,
with ORiNOCO Silver PCMCIA). The laptop works great on
other networks, etc.

But it's not that simple. I can't set the XPDesk
computer as DHCP, because the router is the DHCP. I can
disable DHCP in the router if needed. My laptop never
gets an address (because the router/dhcp isn't on the
wireless link), so it takes a 169.254.x.x for itself. Of
course, now it doesn't hear the XP desktop.

I can set the XP desktop as host, 192.168.0.1, enable ICS
on ethernet interface(again), and then it works but ONLY
between XPDesk and laptop - no internet access (and
probably not to the other computers???)

If I remove the gateway, plug the cable modem directly
into the desktop, (ICS enabled), then XPDesk and internet
works to the laptop, but I no longer have my wired
LAN,just XPDesk and laptop.

I'm a cheapskate and don't want to use a 2nd ethernet
card, or buy a wireless gateway (I have one in the
shop). But mainly, I want to understand what's going on
here, so when it comes up in the future, I'll know what
to do - and WHY. I also like the extra protection the
router offers, in the way of NATS, firewall, etc.

Here's a diagram of my LAN:

Comp2 Comp3 Laptop w/wireless
| | ~
CaMdm>--Router/DHCP>--4PortHub>--XPDesk>-USB-Wireless

Questions:
1. Who's on DHCP? Router or XPDesk?

2. Please give specific examples of proper /ip addresses
for each machine, including the router & laptop, i.e.
router 192.168.0.x, XPDesk 192.168.0.1 DHCP ICS, etc.

3. Do I need routing command on router for for
router>XPDesk>laptop? And on laptop for
laptop>XPDesk>router? Or just XPDesk as gateway? Or
will this be automagically handled?

4. Does the DHCP server automagically have all default
traffic sent to it? If so, how do I make Comp2 & Comp3
internet traffic go directly to the router, and not via
XPDesk?

5. Anything I missed? Any books, docs, homework, etc., I
should read, do, etc.?? I really want to understand the
process.

Thanks very much in advance. And be assured that I will
share this knowledge with others, as I have for many
years, and hope to for many to come.


-mike curtis
ironmanNOSPAM (at) ironmanDIESPAMDIEcurtis <dot> com
Click to expand...


To do what you want, don't use ICS on the desktop.
Don't try to link the machines at IP level, and mess with routing etc.
Try to link them at ethernet level, then there's no routing to mess with.
The machines are now all in one subnet.

Create a network bridge between the wired and wireless connection on the
desktop.
This will link the wired and wireless segments into one segment,
and the router's DHCP will handle the laptop the same as all the others.

This is not always 100%, the bridge can be a bit flakey depending on the
drivers of the network cards involved.

I don't know how well your wireless card will play in the bridge,
you'll need to suck it and see.

Failing that, you need to buy an access point and plug it into your hub :-)
 
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