DNS issues using exchange active sync over WAN



  • I currently use a pfSense in a production environment with 1 wan adapter. The WAN adapter is actually a point to point leased line which doesn't carry any internet traffic so the assigned IP is an internal one in the range of 192.168.0.0/24

    The pfsense box does the dhcp and forwards the dns to an active directory server at the site over the WAN link.

    The problem i am having is that outlook will periodically prompt for user credentials, as if the connection has been lost, this happens on all workstations that are connected through the pfsense box, if I plug into a WAN router, it behaves normally so pfsense appears to be blocking something somewhere but even after looking at the firewall logs i have drawn a blank.

    Could anyone help me resolve this issue?