NDMP server ports
The following list describes the port requirements to backup and restore anNDMP
■ TCP port 10000 must be open from the media server (DMA) to the NDMP filer
(tape or disk) for all types of NDMP operations; local, remote, and 3-way..
■ The NetBackup SERVER_PORT_WINDOW must be open inbound from the
filer to the media server for remote NDMP and also for efficient catalog file
(TIR data) movement during local or 3-way NDMP.
You can test the port at OS-level using telnet command.
The master server does not require access to the NDMP device, only the media server does. If the same host acts as both master and media then of course the machine you call the master does need access, but that's because one machine is perform two roles.