Thank you rof the reply Falko
My servers are connected directly to the Internet.
The workstations I am attempting to access ISPConfig from are however behind a firewall (2).
I have added FW rules to my trunk interceptor and DS1 routers allowing port 81 traffic both in and outward bound.
From any one of my workstations I am able to ping any one of the specific servers running ISPConfig at port 81.
xx.xxx.xxx.x:81 successfully returns pings, this should indidcate that the firewall rule is allowing access to port 81 wouldn't it?
However I am still unable to access ISPConfig on either server VIA web-browser...
Would you still suggest FW tweaking Falko?