Ubuntu + Apache doesn't work on port 80

Question

I have some problems with apache (OS Ubuntu). for some reasons apache doesn't work on port 80.

For this settings: etc/apache2/ports.conf

Listen 80

<IfModule ssl_module>
    Listen 443
</IfModule>

<IfModule mod_gnutls.c>
    Listen 443
</IfModule>

etc/apache2/000-default.conf

<VirtualHost *:80>
    ServerAdmin webmaster@localhost
    DocumentRoot /var/www/html
</VirtualHost>

netstat. I try to connect "my_server_ip" or "my_server_ip:80" browser say "connection closed"

If i change port to 8080(for example) and try to connect "my_server_ip:8080" it's work fine and i see default apache page.

settings: etc/apache2/ports.conf

Listen 8080

<IfModule ssl_module>
    Listen 443
</IfModule>

<IfModule mod_gnutls.c>
    Listen 443
</IfModule>

etc/apache2/000-default.conf

<VirtualHost *:8080>
        ServerAdmin webmaster@localhost
        DocumentRoot /var/www/html
    </VirtualHost>

netstat.

Answer 1

This was my problem:

AllowOverride None

should be changed to

AllowOverride All

Answer 2

For some reasons in Debian GNU/Linux stretch I was able to issue a systemctl start apache2 and seeing it running but not listening. The cause was: the package apache2 was not installed. Really don't know how.

Fixed with:

apt install apache2