You’re installing a new ISA firewall array and you encounter the following error message:

None of the IP addresses of this ISA Server computer are included in the Internal Network for this array

What’s up with that? You configured the default Internal Network correctly during setup, and the internal interface of the ISA firewall has an IP address that part of the definition of the default Internal Network. Is the ISA firewall installed whack?

No, not at all. The problem is that the ISA firewall needs to be able to resolve its own name to the IP address on the internal interface of the ISA firewall. If the ISA firewall can’t resolve it’s own name, then it doesn’t know it exists (just like people with certain dementing disorders or hardware firewall sales guys

Now you might say "hey there, wait a minute buddy, my ISA firewall has the correct name and IP address registered in the DNS and an nslookup against my DNS shows its right!".

That’s may all be true, but did you check your HOSTS file? You might have a HOSTS file entry on the ISA firewall that has the ISA firewall’s name and an incorrect IP address. Gotcha!

Have a good weekend — I’ll be working.

HTH,

Tom

Thomas W Shinder, M.D.

Site: www.isaserver.org

Blog: http://blogs.isaserver.org/shinder/

Book: http://tinyurl.com/3xqb7

MVP — ISA Firewalls