WinXP laptop and two broadband connections

Friends, I have a couple of clients with new WinXP laptops. Turns out they want to use the laptops BOTH in the office and at home.

In the office, there is a DSL connection for which each PC gets a static IP address.
At home, these users have cable modems, one with a DHCP hub connected and one with another computer with internet sharing.

I have tried to use XP's "alternate configuration" tab in TCP/IP properties, but cannot get both connections to work - only one setting (either "obtain an IP address automatically" OR "use this IP address) works. I have searched XP help files and MS's Knowledgebase, but there is nothing of help there.

It does NOT help that Microsoft describes the use of "alternate configuration" with the OPPOSITE of what I want (MS assumes that the OFFICE has automatic IP's, while HOME uses a fixed address...).

As I understand the specs, if XP does not find a DHCP server, it will use the alternate settings for a fixed IP address -- but this is not what happens with my attempts to get a laptop to use a fixed address after it has used an automatic one. In my experience, the laptop just cannot make an "alternate configuration" active ...

I would appreciate your input -- thanks in advance.
Henry N

 

When you say XP cannot make an alternate configuration active, is your original IP address being maintained or are you being assigned a 169.254.y.z address or nothing or the static address (when you check using ipconfig)? Does it make any difference if you do "ipconfig /release" before shutting down?

As an alternative you could use XP's netsh command in a batch file to try each config and use the one that is successful.

 

broadband connections

Thank you for your assistance! I haven't tried netsh, but have learned something by looking it up -

When the laptop is in the OFFICE, I can leave the tcp/ip settings for "automatic" in the first tab, then in "alternate configuration" I can specify a static ip address, and the laptop will connect.

THEN, after the laptop is taken HOME and used on the home connection, any subsequent attempt to connect in the OFFICE fails. IPCONFIG gives an address in the range 192.168.x.x, even thought the correct static values are still in place in "alternate configuration ".

To then get the laptop to connect in the office, I have to clear out all the settings, reboot, and reenter the static IP address.

Perhaps some clearing as you suggest with netsh will help, and I will try that later today. I thought the trigger was just supposed to be the absence of a DHCP server.

Thank you for any additional information -