Apache – Can’t get access to http://localhost:80 on running apache server

On running apache server in ubuntu 14.04 I get "This webpage is not available" in browser or "curl: (7) Failed to connect to localhost port 80: Connection refused" using $ curl localhost. Besides I can connect to 127. * . * . * (e.g. 127.0.0.2) – doesn't work only 127.0.0.1

/etc/hosts

 127.0.0.1  localhost
 127.0.1.1  al-ubuntu
 # The following lines are desirable for IPv6 capable hosts 
 ::1     ip6-localhost ip6-loopback
 fe00::0 ip6-localnet
 ff00::0 ip6-mcastprefix
 ff02::1 ip6-allnodes
 ff02::2 ip6-allrouters

ports.conf

Listen 80

<IfModule ssl_module>
   Listen 443
</IfModule>

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

When I change port e.g. Listen 82 then I can connect to localhost:82 or 127.0.0.1:82

There are no any processes using port 80, except apache2:

$sudo netstat -tulpn | grep 80

=> tcp6 0 0 :::80 :::* LISTEN 7127/apache2

There are three files in /var/log/apache2/:

access.log, error.log and other_vhosts_access.log

When restarting apache2: $ tail -f error.log

 [Thu Feb 19 16:03:19.570066 2015] [mpm_prefork:notice] [pid 1285] AH00169: 
 caught SIGTERM, shutting down
 [Thu Feb 19 16:03:20.673519 2015] [mpm_prefork:notice] [pid 3454] AH00163:   
 Apache/2.4.7 (Ubuntu) PHP/5.5.9-1ubuntu4.6 configured -- resuming normal  
 operations
 [Thu Feb 19 16:03:20.674355 2015] [core:notice] [pid 3454] AH00094: Command line: '/usr/sbin/apache2'

When connecting to localhost in all log files – nothing.

I installed apache on other ubuntu14.04 system and all works.

What cause blocking port 80, do you know in what the problem is?