Red Hat Enterprise Linux 3 / 4 / 5 and above
=> Old Red hat Linux version
=> CentOS 4 and above
=> Fedora Linux
1) Open port 80
Open flle /etc/sysconfig/iptables:
# vi /etc/sysconfig/iptables
Append rule as follows:
-A RH-Firewall-1-INPUT -m state –state NEW -m tcp -p tcp –dport 80 -j ACCEPT
Save and close the file. Restart iptables:
# /etc/init.d/iptables restart
2)Open port 110
Append rule as follows:
-A RH-Firewall-1-INPUT -m state –state NEW -m tcp -p tcp –dport 110 -j ACCEPT
3)Open port 143
Append rule as follows:
-A RH-Firewall-1-INPUT -m state –state NEW -m tcp -p tcp –dport 143 -j ACCEPT
Restart iptables service
Type the following command:
# service iptables restart
Verify that port is open Run following command:
netstat -tulpn | less
Make sure iptables is allowing port 80 / 110 / 143 connections:
iptables -L -n
Refer to iptables man page for more information about iptables usage and syntax:
man iptables