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If your agent is in bidirectional or manager-initiated mode, your hostname must be resolvable in DNS.
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The error: Activation Failed (Unable to resolve hostname) could be the result of an unresolvable hostname in DNS or of activating the agent from Deep Security Manager when you are not using agent-initiated activation. (See Port numbers, URLs, and IP addresses and Create a firewall rule.)
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This error typically occurs when you use Deep Security Manager to attempt to activate a Deep Security Agent and the manager is unable to communicate with the agent. If the issue still occurs, contact Trend Micro Technical Support, and provide the Case Diagnostic Tool (CDT) log generated on the WFBS server and the Security agent.Several events can trigger an "Activation Failed" alert:
#Trend micro security agent listening port Offline
Go to the offline client machine and unload the agent.Use the following workaround if the client is offline after migrating to a new WFBS server or if the client can be updated but doed not appear in the web console after a fresh install: Follow the procedure in this KB article: Migrating clients of Worry-Free Business Security (WFBS) to another server. If the values are not the same, use the Client Mover Tool (IPXfer.exe) to restore the communication between the WFBS server and Security Agent. LocalServerPort - must have the same value as Client_LocalServer_Port.ServerPort - must have the same value as Master_DomainPort.Server - must have the same value as Master_DomainName.The values of the following registry keys should be the same as the values from Step 2:.For 64-bit machine: HKEY_LOCAL_MACHINE\Software\WOW6432Node\Trend Micro\PC-CillinNTCorp\CurrentVersion.For 32-bit machine: HKEY_LOCAL_MACHINE\Software\Trend Micro\PC-CillinNTCorp\CurrentVersion.Open the Registry Editor in the offline/disconnected agent and go to the following registry hive:.Look for the following entries, and take note of their values:.