First, I appreciate ISA 2006 is far from current and there are plans to replace in the new year.
Second, the challenge I face has only occured in the past 3 to 4 weeks and has worked fine for years.
ISA Server 2006 ver 5.02.5723.493
Runing Proxy / Firewall etc
Windows Server 2003 Standard Edition Service Pack 2 Build 3790
Windows last patch - 19 June 2012
Proliant DL360 G5
Our internal DNS domain is configured as (not real domain):
our ISA server is:
our external web site is hosted outside of our network, e.g.
Now, for some reason it is not possible to gain access to www.example.com
Here's what I know:
All other web sites and services are fully operational
When pinging the domain example.com it resolves the correct IP address
Example.com is unavailable from both the ISA server itself and from hosts
When I connect a PC to our DMZ, www.example.com
is fully accessible (ruling out any ISP routing issues)
I have created rules within the Firewall policy to allow all traffic as the number one rule but this has no effect
Within "Configuration", "Networks" and "Internal" I have added the domain and IP address to the "Web Browser" tab to allow direct access but still the problem remains.
So, the ISA box resolves the correct IP Address, it's not an issue from the DMZ, I've tried adding exceptions etc.
Is this a routing issue in that the ISA box doesn't know what to do with requests for www.example.com?
I'm really not sure where to look now, any help would be gratefully received.