There is an alternative to downloading .JDB files and manually dropping them on a Symantec Endpoint Protection Manager (SEPM) to update virus definitions inside an isolated network with no outside connection.
This method may be used to allow a SEPM or Unmanaged Symantec Endpoint Protection (SEP) clients to download and process definition content, including Virus and Spyware, SONAR, and Intrusion Prevention signatures with minimal intervention required.
Initial configuration:
Daily Maintenance