An Exchange Online or Office 365 scenario may fail when Secure Sockets Layer version 3 (SSLv3) is specified in GSX Monitor as the chosen protocol. The Test Connection from the configuration will show as successful, yet the Exchange Scenario will fail during a scan and display an underlying connection error.
This article explains the origin of the error and where to remove the setting.
- The request failed. The underlying connection was closed:
An unexpected error occurred on a send.
How to Solve the Issue
To solve this problem, we need to remove the option that forces SSLv3 in GSX Monitor. By default, GSX Monitor connects with Transport Socket Layer 1 (TLS1) as default, but the URLOPTIONS=SSL3=TRUE setting in GSXScanEngine.ini can override this, and it forces an SSLv3 connection.
If you are monitoring servers or URLs that rely on SSLv3, this option may prevent from scanning them successfully. You may need to establish a new monitoring station for servers or URLs that use the TLS 1.0 protocol.
Here is how to change the protocol setting from SSLv3 to the default TLS 1.0:
- Stop GSX Monitor, including all background processes.
- Locate the GSX Monitor\Data\GSXScanEngine.ini file and open it using a text editor.
- Under the [OPTIONS] section, locate URLOPTIONS.
- Do one of the following:
- If the URLOPTIONS line has more than one key in it, remove only the SSL3=TRUE, and make sure all other entries are separated by a semicolon.
- If the URLOPTIONS line only contains SSL3=TRUE, then remove the entire URLOPTIONS line.
- Save your modifications and close the GSXScanEngine.ini file.
- Launch GSX Monitor.
Exchange scenarios will now run successfully: