Error 2240 on Share Connection - Firewall

If you are getting a error 2240 .. Cannot connect from this workstation on a Lan2Lan VPN connection. First check to see if you can use a local server account vs a domain account.

Using a local account requires ports 137,138,139 and 445 for SMB.

Domain accounts that must authenticate to the LDAP server and use DFS will use more port assignments and you will need to make the required modifications to your firewall.

Distributed File System

The Distributed File System (DFS) integrates disparate file shares that are located across a local area network (LAN) or wide area network (WAN) into a single logical namespace. The DFS service is required for Active Directory domain controllers to advertise the SYSVOL shared folder.

System service name: Dfs

Application protocol	Protocol	Ports
NetBIOS Datagram Service	UDP	138
NetBIOS Session Service	TCP	139
LDAP Server	TCP	389
LDAP Server	UDP	389
SMB	TCP	445
RPC	TCP	135
Randomly allocated high TCP ports	TCP	random port number between 1024 - 65534

Microsofts service overview