I experience an issue accessing Tomcat running over SSL with MS ISA 2006 in front. 

When I access using the internal IP address (e.g. <https://10.0.42.136/..>.) everything works fine and localhost\_access\_log. show me that the query returns a 200. 

However - accessing the same server using FQDN (e.g. <https://mydomain.com/..>.) throws a 403 - Forbidden in the browser. On the Tomcat server I find a 401 error listed not 403. In other words - ISA throw 403 while Tomcat throw 401. 

Both the server hosting the Tomcat as well as the server querying the Tomcat application have full access to the internet. 

I believe there might be an issue with the ISA server as I assume the IP address traffic goes directly while the FQDN traffic goes 'out' before it comes back 'in'. But I am not sure of this. 

Does the Tomcat require any additional configuration to serve https traffic from the outside, e.g. add the IP address of the ISA server, since it works just fine using the IP address?

Do we need to do anything in regards to certificates, as indicated here: <http://webcache.googleusercontent.com/search?q=cache:Y0BozNSUpN4J:forums.isaserver.org/fb.aspx%3Fm%3D2002034493+tomcat+behind+isa+server+certificates&cd=1&hl=no&ct=clnk&gl=no>?

Why does the traffic from my client machine on the outside go just fine, but the traffic from the internal network fails?