Microsoft Dynamics NAV Server is a .NET-based Windows Service application that works exclusively with SQL Server databases.
Microsoft Dynamics NAV Server provides an additional layer of security between clients and the database. It leverages the authentication features of the Windows Communications Framework to provide another layer of user authentication and uses impersonation to ensure that business logic is executed in a process that has been instantiated by the user who submitted the request. This means that authorization and logging of user requests are performed on a per-user basis.
After you install Microsoft Dynamics NAV Server, the default configuration is for the service to log on using the NT Authority\Network Service account. If Microsoft Dynamics NAV Server and SQL Server are on different computers, then MS recommends that you configure Microsoft Dynamics NAV Server to log on using a dedicated Windows domain user account instead. This account should not be an administrator either in the domain or on any local computer. A dedicated domain user account is considered more secure because no other services and therefore no other users have permissions for this account.
Client users can send files to be stored on Microsoft Dynamics NAV Server, so MS recommend that administrators set up disk quotas on all computers running Microsoft Dynamics NAV Server.
This can prevent users from uploading too many files, which can make the server unstable. Disk quotas track and control disk space usage for NTFS volumes, which allows administrators to control the amount of data that each user can store on a specific NTFS volume.
Limiting Port Access
The Microsoft Dynamics NAV Setup program opens a port in the firewall on the computer where you install Microsoft Dynamics NAV Server. By default, this is port 7046.
To improve security, you can consider limiting access to this port to a specific subnet. One way is to use netsh, which is a command-line tool for configuring and monitoring Windows-based computers at a command prompt.
The specific version of this command that you would use is netsh firewall set portopening. For example, the following command limits access to port 7046 to the specified addresses and subnets:
netsh firewall set portopening protocol=TCP port=7046 scope=subnet addresses=LocalSubnet
You can learn more on netsh command here.