In the NetBackup activity monitor, the 'State Details' column reads "Lack of connectivity detected between media server and master server"
There can be errors opening the NetBackup Administration Console, with the error message 'Unable to read configuration: cannot connect on socket (25)'
Backup jobs can also fail with status 25.
If run when the problem is being exhibited, the output of 'netstat -an' can show many nbsl sockets in 'Close_Wait' state.
Insufficient network sockets.
In Admin Console under Netbackup Management/Host properties/Master Servers, open Properties for Master Server.
Select 'Port Ranges'.
Change values for 'Server Port Windows' from the defaults of 1025 to 5000 to 1025 to 32768.
It will be necessary to restart NetBackup on the master server.