Some words about the errors you get which hopefully will save you from similar situations in future.

In Linux ports from 0 to 1024 are reserved for system use. This means that in order to use one, you must have the authority to change - access basic system settings. The root user has such privileges and can actually use a port from the range 0 - 1024.

In your problem as you can see, the system through Apache2 response indicates the root of the problem ([...]could not bind to address blah blah 80):

(13)Permission denied: make_sock: could not bind to address [::]:80

(13)Permission denied: make_sock: could not bind to address 0.0.0.0:80

When the Apache2 http daemon starts, it tries to bind the 80 port as it is the default port for use in HTTP see, which is a port within the system assigned ports and as such it can only be accessed by root.

You executed the start command as a typical user without root privileges and led to failure to do so.

In simple words:

You:

Hi Apache2. I am Kongthap and I am telling you to start (/etc/init.d/apache2 start)

Apache2:

OK. I am starting (Starting web server apache2)

System, please give me port 80 to use and listen for connections.

System:

OK. One moment to check...

Ahh... Sorry Apache2 but I cannot let you run at 80 port, it is for personal use.

And you do not have the correct privileges to bind it. (Operation not permitted)

Apache2:

Ohh, Kongthap I failed to start, the System did not let me do it ((13)Permission denied:[...])

Conclusion

There are mainly two solutions to this problem:

1. Run the Apache2 HTTP daemon with root privileges using sudo:

   
   

   sudo service apache2 start
   
   

   
   

   or:

   
   

   sudo /etc/init.d/apache2 start
   
   

   
   



2. Change the default port from 80 to something greater than 1024, say 2000, 2500, 9000, etc. A typical port to run when in such situation is 8080

   
   

   sudo vi /etc/apache2/ports.conf
   
   

   
   

   look for or if not there add:

   
   

   Listen 8080
   
   

   
   

   or any other port of your choice such as port > 1024 and the selected port is not used by another process.