We have a mail server (with a web interface on port 80) set up behind the firewall. We cannot access it using standard URLs, we have to use IP addresses.This is a known problem with the RF650VPN due to the Linux kernel that is used inside the RF650VPN. We are working on a permanent solution to this problem.
Here are a few work around options:
1) Setup LMHOSTS file on the workstation so the name is assign to private IP address.
2) If you are hosting your own internal DNS server and all the workstations are pointing to the internal DNS server, then you can add an entry in the DNS server to resolve the name to the private IP address.