In Chrome, if you attempt to access a website on some non-standard ports, such as port 123, you will see:

"This webpage is unavailable" and the text of your error will be: Error 312 (net::ERR_UNSAFE_PORT): Unknown error.

To fix this, you have to explicitly allow the unsafe port when you start up chrome.

Right click on your chrome icon that you use to launch chrome, and click properties.

In the TARGET Textbox which is something like this:

C:\Users\sanjay\AppData\Local\Google\Chrome\Application\chrome.exe

To allow ports 123, 124, change it to:

C:\Users\sanjay\AppData\Local\Google\Chrome\Application\chrome.exe --explicitly-allowed-ports=123,124