Checking if the network has changed

[Dave Cragg]

On 20 Apr 2006, at 23:10, Alex Tweedly wrote:

>
> Let me give you some more to think about then, in the context of  
> large corporate nets  :-)

Again thanks, Alex.

> you just need to find the right IT guy

But just when you find him, and he's halfway through setting  
everything up for you, he gets transferred or outsourced. :-)


>
> One possible approach : provide a service on the proxy which can be  
> firewalled such that it is not reachable from "the Internet" (this  
> is very likely very easy - most corporations firewall as much as  
> they can, so simply an echo server on a suitable (perhaps UDP) port  
> would do).  The client starts by trying to reach that service - and  
> if it gets a response, then it must be on the corporate net; if  
> not, it is elsewhere and shouldn't try to use the proxy.

Would a dns lookup on the proxy server (assuming it uses a name and  
not a number) achieve the same? The main reason for hosting this  
externally was to avoid reliance on internal IT as much as possible.

Cheers
Dave