Port issues

[servettonga]

• In the configuration file set up multiple ports and use different websites. Use the browser to ensure that the configuration works as expected and shows the right website.
• In the configuration, try to set up the same port multiple times. It should not work.
• Launch multiple servers at the same time with different configurations but with common ports. Does it work? If it does, ask why the server should work if one of the configurations isn't functional.