Home Network - catch 22 with ICS

[David Fallen]

For over a year I have had a great home network with sharing of the internet
via a cable modem. Well, the host crashed and I had to reinstall Windowx XP
and everything else. Alas, I cannot get ICS to work.

When I attempt to enable ICS on the host computer, I get the message that
Internet Connection Sharing cannot be enabled because the IP address
192.168.0.1 is already being used. Sure enough, if I run IPCONFIG I find my
Default Gateway, DHCP Server, and DNS Servers show up as 192.168.01. BUT,
the NIC is set up to get its addresses via DHCP.

So what have I forgotten to do? Obviously, since this used to work, I have
forgotten a step or setting somewhere. Here is the whole setup:

CLIENT COMPUTER (using Windows ME):
IP Address 172.16.0.2
Subnet Mask 255.255.0.0
Default Gateway 172.16.0.1
DHCP Enabled: No
(Since this always worked in the past and this computer didn't crash, I
haven't played with these settings.

The Client Computer connects to the HOST COMPUTER (Windows XP Home) with the
following settings:
IP Address 172.16.0.1
Subnet Mask 255.255.0.0
DHCP Enabled: No
Default Gateway: (none)
The home network is working.

With a second NIC card, the host computer connects to a router which
connects to the cable modem. The setting are:
DHCP Enabled: Yes
Autoconfiguration Enabled: Yes
IP Address 192.168.0.100
Subnet Mask 255.255.255.0
Default Gateway 192.168.0.1
DHCP Server 192.168.0.1
DNS Servers 192.168.0.1

Any help would be appreciated!

 

[Steve Winograd [MVP]]

For over a year I have had a great home network with sharing of the internet
via a cable modem. Well, the host crashed and I had to reinstall Windowx XP
and everything else. Alas, I cannot get ICS to work.

When I attempt to enable ICS on the host computer, I get the message that
Internet Connection Sharing cannot be enabled because the IP address
192.168.0.1 is already being used. Sure enough, if I run IPCONFIG I find my
Default Gateway, DHCP Server, and DNS Servers show up as 192.168.01. BUT,
the NIC is set up to get its addresses via DHCP.

So what have I forgotten to do? Obviously, since this used to work, I have
forgotten a step or setting somewhere. Here is the whole setup:

CLIENT COMPUTER (using Windows ME):
IP Address 172.16.0.2
Subnet Mask 255.255.0.0
Default Gateway 172.16.0.1
DHCP Enabled: No
(Since this always worked in the past and this computer didn't crash, I
haven't played with these settings.

The Client Computer connects to the HOST COMPUTER (Windows XP Home) with the
following settings:
IP Address 172.16.0.1
Subnet Mask 255.255.0.0
DHCP Enabled: No
Default Gateway: (none)
The home network is working.

With a second NIC card, the host computer connects to a router which
connects to the cable modem. The setting are:
DHCP Enabled: Yes
Autoconfiguration Enabled: Yes
IP Address 192.168.0.100
Subnet Mask 255.255.255.0
Default Gateway 192.168.0.1
DHCP Server 192.168.0.1
DNS Servers 192.168.0.1

Any help would be appreciated!

Your network has a router, and a router's purpose is to share a cable
modem connection between multiple computers. If you can connect both
computers to the router, there's no need for ICS.

If you must use ICS for some reason, the problem that you're having is
because both the router and ICS, by default, use the 192.168.0.x range
of IP addresses. It appears that you've changed the ICS IP addresses,
but Microsoft doesn't support using anything but 192.168.0.x for ICS,
and there's no guarantee that ICS will work if you change it. The
best solution would be to use different address ranges:

1. Disable ICS on the host computer.

2. Configure the client computer's TCP/IP settings to obtain an IP
address automatically.

3. Connect to the router's web server (http://192.168.0.1) from the
host computer and configure the router to use a different IP address
range, such as 192.168.1.x.

4. Enable ICS on the host computer.
--
Best Wishes,
Steve Winograd, MS-MVP (Windows Networking)

Please post any reply as a follow-up message in the news group
for everyone to see. I'm sorry, but I don't answer questions
addressed directly to me in E-mail or news groups.

Microsoft Most Valuable Professional Program
http://mvp.support.microsoft.com

 

[David Fallen]

Thanks, Steve. I changed the router address to 192.168.1.1 and was then
able to enable ICS. I still didn't have internet connection from the client
with the static IP address I have always used. I changed the client's
TCP/IP to obtain an IP address automatically (as you instructed). Lo and
behold, it works! I don't understand why it works given that the host
adapter that connects to the client is still a static address, but the proof
is in the pudding.

Thanks Steve!

 

[Steve Winograd [MVP]]

Thanks, Steve. I changed the router address to 192.168.1.1 and was then
able to enable ICS. I still didn't have internet connection from the client
with the static IP address I have always used. I changed the client's
TCP/IP to obtain an IP address automatically (as you instructed). Lo and
behold, it works! I don't understand why it works given that the host
adapter that connects to the client is still a static address, but the proof
is in the pudding.

Thanks Steve!

You're welcome, David. I'm glad that my suggestions helped you solve
the problem.

The host computer's LAN connection has a static IP address of
192.168.0.1 The client computer gets a dynamic IP address in the
range 192.168.0.2-192.168.0.254 from the host computer. What's
important is that the IP addresses are in the same subnet. It makes
no difference that one's static and one's dynamic.
--
Best Wishes,
Steve Winograd, MS-MVP (Windows Networking)

Please post any reply as a follow-up message in the news group
for everyone to see. I'm sorry, but I don't answer questions
addressed directly to me in E-mail or news groups.

Microsoft Most Valuable Professional Program
http://mvp.support.microsoft.com