I tried to run a CentOS Apache2 / PHP / MySQL server on a LAN (With 10.x.x.x IP).
OS : CentOS release 6.7 (Final)
I checked if the services is running, they're still working.
[root@srv-annuaire-01 ~]# /etc/init.d/httpd status
httpd (pid 2542) en cours d'exécution... *(running)*
[root@srv-annuaire-01 ~]# /etc/init.d/mysqld status
mysqld (pid 1795) en cours d'exécution... *(running)*
Edit : That's the service iptables who's blocking us.
In apache2 config file add
listen port_no
or
/etc/init.d/iptables stop
and restart your server