If a sensor fails to connect to the backend, it tries the last known working settings, starting with the most recent ones.

These include the following:

  • Proxy
  • No proxy
  • Credentials
  • No credentials
  • Proxy used at install time
  • Direct connection
  • Alternate 54443 port

If the sensor cannot connect using its last valid settings, it reattempts the connection in the following sequence:

  1. The proxy server that was provided during sensor installation (if applicable).
  2. Variants of the proxy that was set during sensor installation (if applicable). These variants are with or without credentials using default port (443) and the alternate port (54443).
  3. A direct connection to the backend with no proxy and default port (443).
  4. A direct connection to the backend with no proxy using the alternate port 54443.
  5. Dynamically set proxies such as:
    • Proxies configured within inetcpl.cpl (Internet Options) – For each server, also try default (443) and alternate (54443) ports.
    • .pac files configured within inetcpl.cpl – For each server, also try default (443) and alternate (54443) ports.
    Note: Sequence numbers 1 and 2 can be switched by using PreferStaticProxyOverLastUsed=trueas described in Configure a Proxy for Windows after Sensor Installation.