HTTPD non available from remote computer - apache

Question

I've just installed a Nagios on Centos 7.
I followed the same procedure used for my test environment.
Only difference between test and prod is that the server was not prepared by me, but was an automatic provisioning.
Anyway, i'm failing to undestand why the Nagios web page (and the Apache standard page) is not reachable.
I've already checked with network team for ports blocked and they told me that the traffic is not blocked.
What is wrong with this server?
Here is the config.
# netstat -tunlp
Active Internet connections (only servers)
Proto Recv-Q Send-Q Local Address Foreign Address State PID/Program name
tcp 0 0 0.0.0.0:3306 0.0.0.0:* LISTEN 1503/mysqld
tcp 0 0 0.0.0.0:80 0.0.0.0:* LISTEN 12139/httpd
tcp 0 0 127.0.0.1:50000 0.0.0.0:* LISTEN 616/oneagentwatchdo
tcp 0 0 127.0.0.1:50001 0.0.0.0:* LISTEN 616/oneagentwatchdo
tcp 0 0 127.0.0.1:50002 0.0.0.0:* LISTEN 616/oneagentwatchdo
tcp 0 0 127.0.0.1:50003 0.0.0.0:* LISTEN 616/oneagentwatchdo
tcp 0 0 0.0.0.0:22 0.0.0.0:* LISTEN 1758/sshd
tcp 0 0 127.0.0.1:25 0.0.0.0:* LISTEN 1568/master
tcp6 0 0 :::22 :::* LISTEN 1758/sshd
tcp6 0 0 ::1:25 :::* LISTEN 1568/master
udp 0 0 0.0.0.0:68 0.0.0.0:* 837/dhclient
udp 0 0 127.0.0.1:323 0.0.0.0:* 565/chronyd
udp6 0 0 ::1:323 :::* 565/chronyd
FirewallD is "Inactive".
Even if was active the list of port and service would be:
# firewall-cmd --list-all
public (active)
target: default
icmp-block-inversion: no
interfaces: eth0
sources:
services: dhcpv6-client http ssh
ports: 80/tcp
protocols:
masquerade: no
forward-ports:
source-ports:
icmp-blocks:
rich rules:
Iptables is not installed and therefore not active
SELinux status: disabled
I'm still thinking that there is a block somewhere but i cannot identify where it could be.