How to switch proxy on/off automatically on work laptops

[MarcLister]

I started a new job in a school on Monday. All the staff get laptops which run Sophos AV. To update itself Sophos has to use the school proxy when the laptops are within the school and therefore using the school network. When the teachers take the laptops home the school proxy isn't available and so Sophos can't update itself as long as the laptops are away from the school network. Is there a way to get the laptops to turn the proxy on and off depending on which network they are currently connected to?

I wouldn't ask the staff to change the proxy settings as this would lead to massive problems and all the laptops run XP or Vista so I'm guessing the XP laptops are probably quite light on built-in abilities to do something like this. Is there some kind of Windows app that could force XP or Vista to use the teachers' home network when the laptop is connected to their network and then restore the school proxy when back at school?

[burble]

How about dishing out proxy settings using DHCP and setting the browsers to automatically detect settings? DHCP option 252 is what you need, link.

That way when the laptop is at the school it'll get the proxy server details when the browser starts but when at home it won't so it'll go direct.

[burble]

Or a variation on the theme, point the web browser to a wpad.dat script on an internal webserver somewhere. When at the school the browser will download the script and follow it when when at home the script won't be available so it'll ignore it and go direct.

[MarcLister]

How about dishing out proxy settings using DHCP and setting the browsers to automatically detect settings? DHCP option 252 is what you need, link.

That way when the laptop is at the school it'll get the proxy server details when the browser starts but when at home it won't so it'll go direct.

Well I was going to ask on another forum but your reply kind of stops me from doing that.

I like this idea so I'll see if we can work on that at school.

Or a variation on the theme, point the web browser to a wpad.dat script on an internal webserver somewhere. When at the school the browser will download the script and follow it when when at home the script won't be available so it'll ignore it and go direct.

Sounds cool also. Is it fairly easy to knock up a wpad.dat script? Kind of thing I can google fairly easily?

[burble]

Well I was going to ask on another forum but your reply kind of stops me from doing that.

I like this idea so I'll see if we can work on that at school.

I've got this solution working for sites using DHCPD on Linux and also the iffy DHCP server in Windows 2003 server. TBH any DHCP server should support it.

Sounds cool also. Is it fairly easy to knock up a wpad.dat script? Kind of thing I can google fairly easily?

Absolute doddle. From what I remember the syntax is a bit JavaScript-esque. You could also google for proxy.pac, they're pretty much the same thing. You can do clever stuff with the scripts - set the browser to only use the proxy for external sites, bypass for certain and so on.

[MarcLister]

I've got this solution working for sites using DHCPD on Linux and also the iffy DHCP server in Windows 2003 server. TBH any DHCP server should support it.

We've got Server 2003 so I might look into this.

Absolute doddle. From what I remember the syntax is a bit JavaScript-esque. You could also google for proxy.pac, they're pretty much the same thing. You can do clever stuff with the scripts - set the browser to only use the proxy for external sites, bypass for certain and so on.

Fantastico.

My boss was moaning about how people put their own AVs on the laptops but if the Sophos AV can't update at weekends/half-terms/summer hols etc then I'm not surprised they've installed AVG, Avast etc. So I want to find a way of having Sophos work at home and at schoo. Next I plan to rid the laptops of Sophos because I don't really rate it. I think we get it as part of a yearly contract with an IT support firm so I might have a fight on my hands to change to NOD or Kaspersky or something else.