Convenience wrapper tool that utilizes ike-scan and interprets the output to analyze VPN connectivity from a certain environment.
https://github.com/royhills/ike-scan
http://nta-monitor.com/wiki/index.php/Ike-scan_User_Guide
https://github.com/royhills/ike-scan/releases
Note: only Windows binaries available for download. For other OSes, you need to build from source.