Chrome Connectivity Diagnostics

Chrome Connectivity Diagnostics is an extension that performs several network-based tests.  The tool tests a computer's network connection for common issues, port blocking, and network latency by establishing connections to network and Internet services via UDP, TCP, HTTP and HTTPS.

https://chrome.google.com/webstore/detail/chrome-connectivity-diagn/eemlkeanncmjljgehlbplemhmdmalhdc