问题
I gave an answer to following thread. but in the comment a user suggested that network admin can change the default port of http from 80 to something else. As for as I know if I open a page eg. http://www.example.com without port that means it is running on port 80.
I just want to clarify that is it possible for network admin to change default port?
回答1:
When using a browser, http://www.example.com will always try and connect to the server's TCP port 80, like it's port 443 for HTTPS connections. These port numbers (defined here) are hard coded in any browser.
Yet a web server can be configured to listen to any other port, which rarely makes sense though. If it does, the browser will be unable to connect (unless the port no. is explicitly given as in http://myserver.com:81).
来源：https://stackoverflow.com/questions/12601397/can-network-admin-change-the-default-port-for-http