Enable 80 port in CentOS

If you did an Apache installation then you also need to enable 80 port in iptables:

iptables -I INPUT 5 -i eth0 -p tcp --dport 80 -m state --state NEW,ESTABLISHED -j ACCEPT

eth names in CentOS

To make sure particular device name will be assigned to particular ethernet card (there are 2 on my server) I needed to do the following:

$ vi /etc/udev/rules.d/70-persistent-net.rules 
SUBSYSTEM=="net", ACTION=="add", DRIVERS=="?*", ATTR{address}=="00:ef:88:45:88:44", NAME="eth0"
SUBSYSTEM=="net", ACTION=="add", DRIVERS=="?*", ATTR{address}=="90:e6:ba:ef:80:db", NAME="eth1"

How to change hostname in Centos

Commands to change hostname in Centos

sudo sed -i 's/<old name>/<new name>/g' /etc/sysconfig/network /etc/hosts
sudo hostname <new name>

And after log of and log in – the hostname will be