access to the client was not allowed
The master or the media server tries to access the client, but the client does not recognize the server as a valid server.
Solution 1: NetBackup Master Server
S1-1. Run NetBackup Administration Console
S1-2. Navigate to NetBackup Management -> Host Properties -> Clients
S1-3. Select the client or press CTRL to select multiple clients.
S1-4. Right click and select Properties
S1-5. Add Media Servers entry
S1-6. Click OK to apply
Solution 2: NetBackup Client
S2-1. Run NetBackup Client Console Backup, Archive, and Restore
S2-2. Open menu File and select Specify NetBackup Machines and Policy Type…
S2-3. Next, Click Edit Server List button
S2-4. Enter Media Server Hostname and click Add Name(s) to Server list. Next, click OK twice to apply.
S2-5. The entry from Item 4 will be added in Additional Servers.
To check from NB Master server, Open Properties from Client Host Properties