Office 1 - Mydomain.local
Server1 - AD/DC, DNS, DHCP - IP: 10.1.0.0/24
Server2 - Sharepoint 2013

Office 2 - Mydomain.local
Server3 - DC, DNS, DHCP - IP: 10.2.1.0

I am having troubles getting users from Office 2 to access sharepoint which is hosted in Office1.
Office1 and Office2 are in different cities and are both connected via VPN and are both part of MYDOMAIN.LOCAL

From Server3 in office2 I am able to ping Server2 (sharepoint) with IP, hostname, FQDN, and sharepoint site name.

When users from Office2 try to access Sharepoint via http://intranet, they will get the windows security window asking for domain credentials. The security window will keep prompting not allowing access. After 5 attempts (with the correct credentials) it shows up with just a blank page. No errors are logged.

Hi,

According to your description, my understanding is that users fail to access SharePoint via http://intranet.

It seems that the issue may be caused by the authentication via VPN. Please monitor the request and response of the VPN authentication using Fiddler, it will give you more details about how to troubleshoot this issue.

Also, you could configure your router as below:

Modem >> router >> switch >> lan1 >> computers in lan1

                                                >> lan2 >> computers in lan2

Reference:

http://stackoverflow.com/questions/14474346/how-to-communicate-hosts-in-different-subnet

Best Regards,

Dea