For customers using their own domain name, we recommend using internal DNS to force any site traffic as local. So for example, internally, share.yourcompany.com should resolve to the internal IP address. This greatly speeds up internal access and bypasses any firewall issues NAT'ing back to itself. This is standard practice for any internally hosted website - for example Exchange Outlook Web Access.
On a DC in your internal Windows Domain open DNS manager:
1. Create a new Forward Lookup Zone.
2. Set the type to Primary (AD Integrated as well if you like).
3. Name the zone "share.yourcompany.com".
4. Finish off the wizard, leaving dynamic update disabled.
5. Select the zone then create a new Host (A) record with a blank name.
6. Enter the private IP address.
Note: this will not effect name resolution for any other resource beneath
company.com, as the system only claims authority for share.company.com.