Trend Micro Office Scan Server Manual Updates.

You need to configure your "Air Gapped" Server as an Update Agent Server.

Here's how...

Configuring Update Agents is a three-step process:
 
1.  Grant clients the privilege to act as update agents.
2.  Select an update source from which the Update Agent can receive updated components.
3.  Select which clients you want to update from the Update Agent and set the Update Agents as the client update source.
   
A. Specifying a Client as an Update Agent
 
1.  On the sidebar, click Clients. The domain tree for the Clients screen appears.      
2.  Click the domains or clients that will be granted Scheduled Update privileges by clicking the corresponding icons in the domain tree. To select all domains and clients, click the root icon.    
3.  On the sidebar, click Client Privileges/Settings.      
4.  Under Update, select the Act as Update Agent check box.
 
   Note: If you select multiple clients, you cannot modify the Act as Update Agent privilege. To change this privilege for multiple clients at one time, create and export a policy for Client privilege settings. Then select multiple clients and import the policy. The client privilege settings, including the Act as Update Agent privilege, are applied to all selected clients.
       
5.  Click Save. Clients that act as update agents appear with the icon in the domain tree.
     
B. Selecting an Update Agent Update Source
 
Enable Update Agents to get their component updates from the OfficeScan server on the Update Agent screen. If you do not enable Update Agents to get component updates from the OfficeScan server, they receive updates from the source specified on the Update Source screen.
 
1.  On the sidebar, click Updates > Client Deployment > Update Agent. The Update Agent screen appears.      
2.  Click the Always update from standard update source (OfficeScan server) to have agents always get updates from the OfficeScan server.
 
   To have agents get updates from the sources specified on the Update Source screen, clear the check box.
     
3.  Click Save.
     
C. Setting an Update Agent as a Client Update Source
 
To have OfficeScan clients get their updates from one or more Update Agents, add the Update Agent(s) to the Customized update source list in the Update Source screen. You can also specify (by IP address) which clients receive updates from any update source.
 
1.  On the sidebar, click Updates > Client Deployment > Update Source. The Update Source screen appears.      
2.  Click Customized Update Source.    
3.  In the Customized Update Source list, click Add. The Add IP Range and Update Source screen appears.      
4.  Type a range of IP addresses of clients that will receive updates from an Update Agent.      
5.  Next to Update Source, click Update Agent and select an agent from the list.
 
   Note: The clients that have been granted the privilege to act as Update Agents appear in the list. If any Update Agents are missing, apply the Act as Update Agent privilege to the clients in the Client Privileges and Settings screen.
     
6.  Click Save.