Why is the proxy server unable to deliver http requests back to the local lan

[Sheraz_35]

Hi, something is bugging me, we have a proxy server that all our web traffic goes through, however when we try to access websites hosted internally on site, we can not access them unless we disable the proxy server in I.E settings, I was just wondering why doesn't the proxy server deliver http requests to websites hosted locally on site? I am presuming that the traffic would go from the proxy server to the default gateway router, shouldn't the default gateway router just deliver the HTTP requests to the internally hosted website? 

[Jon Marshall]

Difficult to say without knowing how you have it all setup.

I can tell you what we did though when we used a proxy server.

We used AD and group policy to set the proxy server in users web browsers (I say we but it was the server guys, no idea about configuring AD etc. :-)).

You can add exceptions to this and we added an exception for our internal domain name so the browser would ignore the proxy server setting for internal requests and go direct to the web servers.

Jon

[Aaron Harrison]

It's pretty common to use a Proxy PAC file to split traffic out between internal/direct accessed websites and the rest which would go via the Proxy.

http://findproxyforurl.com/example-pac-file/

There could be lots of reasons why what you are trying wouldn't work on your proxy - can it resolve internal server names with the DNS servers it is configured with? Are there firewalls preventing it from accessing the internal websites? Etc.

Aaron

[Jon Marshall]

Aaron

That was it, a proxy PAC file.

I knew there was a name for it I just couldn't remember it :-)

Jon

[Aaron Harrison]

Hi Jon

To be fair, you can (as you suggested) just push out a proxy server, with a static bypass list. The advantage of the PAC approach is that if the device moves off network (i.e. laptop taken home) it can fail 'open' and connect out direct to the Internet without user intervention.

Aaron

[Sheraz_35]

Hi guys, I appreciate your replies, I just noticed the "bypass proxy server for local addresses" tickbox in I.E settings, doh!!!