Help Center/ Server Migration Service/ FAQs/ Error Codes and Solutions/ SMS.0305 Failed to Connect to the Proxy Server
Updated on 2026-07-13 GMT+08:00

SMS.0305 Failed to Connect to the Proxy Server

Symptom

When the SMS-Agent is started, the error message "SMS.0305: Failed to connect to the proxy server." is displayed.

Possible Causes

This problem usually occurs when a proxy server is used for private network migration. After the SMS-Agent is started on the source server, it attempts to access SMS through the proxy server. If the HTTPS protocol versions supported by the source server and proxy server are incompatible, an error message will be displayed.

Solution

Adjust the proxy configuration parameters of the SMS-Agent to make it compatible with the proxy server.

  1. Log in to the source server.
  2. Modify the SMS-Agent proxy configuration.

    • Linux source server
      Go to the SMS-Agent installation path. Use the file editor to modify the auth.cfg file in the SMS-Agent/agent/config directory and save the modification.
      vim SMS-Agent/agent/config/auth.cfg
      [proxy-config]
      proxy_addr = {Proxy server domain name/IP address}
    • Windows source server
      • For Python 3, access the SMS-Agent GUI, select Use Proxy, and enter the intranet IP address of the proxy server in the Proxy server IP text box.

      • For Python 2, go to the Agent installation directory, for example, C:\SMS-Agent-Py2\config, modify the auth.cfg file, and save the modification.
        [proxy-config]
        proxy_addr = {Proxy server access domain name/IP address}

  3. Save the modification and restart the SMS-Agent for Python 2. Start the Agent for Python 3.