ICS: How to use a different subnet?

[Ulf Schaper]

Hi folks,

I want to use ICS (Internet Connection Sharing) with Windows XP
Professional acting as the server, but it cannot use the
192.168.0.x-subnet, because my Internet Gateway already uses these
addresses:

Internet Connection (I cannot change this)
------------------------------------------
My IP: 192.168.0.67
Gateway: 192.168.0.1


Local network
------------------------------------------
My IP: 192.168.1.1

So, please tell me, is there a way to make ICS use 192.168.1.x-addresses
for the Server and for the DHCP-address-assigning?
I remember some registry keys which worked for Windows 98, but they are of
course not working for Windows XP...

Thanks in advance for any hints,
Ulf Schaper

 

[Lanwench [MVP - Exchange]]

Hi folks,

I want to use ICS (Internet Connection Sharing) with Windows XP
Professional acting as the server, but it cannot use the
192.168.0.x-subnet, because my Internet Gateway already uses these
addresses:

Internet Connection (I cannot change this)
------------------------------------------
My IP: 192.168.0.67
Gateway: 192.168.0.1


Local network
------------------------------------------
My IP: 192.168.1.1

So, please tell me, is there a way to make ICS use
192.168.1.x-addresses for the Server and for the
DHCP-address-assigning?
I remember some registry keys which worked for Windows 98, but they
are of course not working for Windows XP...

Thanks in advance for any hints,
Ulf Schaper

OT, but if you have a gatway device doing NAT already, why do you want to
use ICS? Why can't everyone just get a DHCP-configured address from that
device and use it as the default gateway to connect to the Internet?

 

[Steve Winograd [MVP]]

Hi folks,

I want to use ICS (Internet Connection Sharing) with Windows XP
Professional acting as the server, but it cannot use the
192.168.0.x-subnet, because my Internet Gateway already uses these
addresses:

Internet Connection (I cannot change this)
------------------------------------------
My IP: 192.168.0.67
Gateway: 192.168.0.1


Local network
------------------------------------------
My IP: 192.168.1.1

So, please tell me, is there a way to make ICS use 192.168.1.x-addresses
for the Server and for the DHCP-address-assigning?
I remember some registry keys which worked for Windows 98, but they are of
course not working for Windows XP...

Thanks in advance for any hints,
Ulf Schaper

I'm sorry, but XP's ICS wasn't designed to allow changing the subnet.

You can manually change the IP address of the host's LAN connection to
a 192.168.1.x address. However, that's an un-supported configuration,
and there's no guarantee that ICS will work after that. If it's your
only choice, then it's worth a try. Make a restore point on the host
beforehand so that you can restore it in case of problems.

Changing the host's LAN IP address will disable the host's DHCP
server, so you'll have to manually assign TCP/IP properties on the
client computers. For example, if you assign 192.168.1.1 to the host,
make these assignments on the clients:

IP Address: 192.168.1.x (1<x<255)
Subnet Mask: 255.255.255.0
Default Gateway: 192.168.1.1
DNS Server = 192.168.1.1 or your ISP's DNS server

Two questions for you:

1. Since you have an Internet gateway, why do you need ICS? Can the
client computers connect to the same gateway? If not, it's likely
that setting up a network bridge, not ICS, on the host computer will
solve the problem. I've written a web page with details:

XP ICS - Network Bridge
http://www.practicallynetworked.com/sharing/xp_ics/networkbridge.htm

2. Have you considered getting an inexpensive home broadband router
(which CAN change its LAN IP address) and using it, instead of ICS, to
share the connection from the existing Internet gateway?
--
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

 

[Ulf Schaper]

You can manually change the IP address of the host's LAN connection to
a 192.168.1.x address. However, that's an un-supported configuration,
and there's no guarantee that ICS will work after that. If it's your
only choice, then it's worth a try.

Thank you very much, this worked!

When I first tried it, I got an error message telling me that it was not
possible to install ICS because 192.168.0.x was already in use
(192.168.0.67 in my case). I temporarily assigned another (192.168.2.x)
IP to this adaptor, then I activated ICS, and afterwards I restored all
IPs to their original ones.

1. Since you have an Internet gateway, why do you need ICS?  Can the
client computers connect to the same gateway?  If not, it's likely
that setting up a network bridge, not ICS, on the host computer will
solve the problem.  [...]

My Internet Connection is a Wireless Network, so the other local computers
cannot access it (I am not willing to buy a wireless network adaptor for
each one). A bridge also wouldn't help me because my provider does not
give me more than one IP in the 192.168.0.x-subnet.

2. Have you considered getting an inexpensive home broadband router
(which CAN change its LAN IP address) and using it, instead of ICS, to
share the connection from the existing Internet gateway?

Yeah, I've thought about this! I have an old D-Link DWL-700AP access
point, I tried to use it's "wireless client" function but I couldn't
really make it work (I am still open for suggestions on this piece of
hardware!).

Again, Thank you very much, Steve!

Ulf Schaper

 

[Steve Winograd [MVP]]

You can manually change the IP address of the host's LAN connection to
a 192.168.1.x address. However, that's an un-supported configuration,
and there's no guarantee that ICS will work after that. If it's your
only choice, then it's worth a try.

Thank you very much, this worked!

When I first tried it, I got an error message telling me that it was not
possible to install ICS because 192.168.0.x was already in use
(192.168.0.67 in my case). I temporarily assigned another (192.168.2.x)
IP to this adaptor, then I activated ICS, and afterwards I restored all
IPs to their original ones.

1. Since you have an Internet gateway, why do you need ICS?  Can the
client computers connect to the same gateway?  If not, it's likely
that setting up a network bridge, not ICS, on the host computer will
solve the problem.  [...]

My Internet Connection is a Wireless Network, so the other local computers
cannot access it (I am not willing to buy a wireless network adaptor for
each one). A bridge also wouldn't help me because my provider does not
give me more than one IP in the 192.168.0.x-subnet.

2. Have you considered getting an inexpensive home broadband router
(which CAN change its LAN IP address) and using it, instead of ICS, to
share the connection from the existing Internet gateway?

Yeah, I've thought about this! I have an old D-Link DWL-700AP access
point, I tried to use it's "wireless client" function but I couldn't
really make it work (I am still open for suggestions on this piece of
hardware!).

Again, Thank you very much, Steve!

Ulf Schaper

You're welcome, Ulf. I'm glad that it worked for you. Thanks for the
update.
--
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