Server connecting from/to random ports during backup

[CrazyKen]

Server: Windows 2003 R2 with SP2 and all hotfixes
Software: Backup Exec for Windows Servers 12.5 with SP2 and all hotfixes
Remote host: Linux
Agent: RALUS

When a backup starts, it mainly connects to the remote agent via NDMP on port 10000, but will also use random ports throughout the backup process.  If I re-enable the firewall on the remote host and allow only port 10000 traffic between my backup server and this host, the backup job fails within 10-15 seconds after the job begins.  If I re-run the same backup job, the server will choose another set of random source and destination ports.  

Attached to this post is 5 separate Wireshark captures of a test job showing the server connecting from random ports for each job.

On the server, I do *not* have it enabled to use dynamic ports under Tools -> Options -> Network & Security.  All of the documentation I can find regarding remote agents state that it will use NDMP, but will use random ports if NDMP is unavailable.  Well, NDMP is available, so my questions are:

1. Why is the server using random ports?

2. How can I have it communicate with the remote host only via NDMP on port 10000?

[Colin_Weaver]

 The NDMP Control Connection is on Port 10000, NDMP also needs one or more Data connections which are your random ports

You can narrow the range by setting the option in Tools --> Options --> Network and Security in the Backup Exec Console on the media server.
However make the range between 20 and 50 ports otherwise problems are likely to occur - i.e. don't set it to 1 port