Redhat / CentOS / Fedora Linux Open Port
Q. I’ve Redhat Enterprise Linux 5 server with Iptabeles firewall enabled. By default it is only allowing port 22. How do I open port 80 / 143 / 110 on Linux? I've started all services but don't know how to open port using iptables.
A. By default iptables firewall stores its configuration at /etc/sysconfig/iptables file. You need to edit this file and add rules to open port number. This file only avilable under
Red Hat Enterprise Linux 3 / 4 / 5 and above
=> Old Red hat Linux version
=> CentOS 4 and above
=> Fedora Linux
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
Open port 110
Append rule as follows:
-A RH-Firewall-1-INPUT -m state --state NEW -m tcp -p tcp --dport 110 -j ACCEPT
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
Subscribe to our free e-mail newsletter or RSS feed to get all updates.
You can Email this page to a friend.
Related Linux / UNIX FAQ:
- How to: Allow telnet and ssh through iptables under Linux
- Iptables open ftp port 21
- How do I block an IP on my Linux server?
- Linux disable or remove the iptables firewall
- Howto Secure portmap service using iptables and TCP Wrappers under Linux
Discussion on This FAQ
Leave a Reply
We encourage your comments, and suggestions. But please stay on topic, be polite, and avoid spam. Please do not use the comment form to ask for help / question. Ask your question on the excellent Linux tech support forum. Thank you very much for stopping by our site!
Tags: centos_open_port, enterprise_linux, fedora_linux, fedora_open_port, firewall_open_port, iptables_firewall, linux_open_port, open_tcp_port, redhat_open_port, red_hat_linux, rhel_open_port
February 12th, 2008 at 2:24 pm
Save and close the file. Restart iptables:# /etc/init.d/iptables restart
How to close and save a file?????
March 19th, 2008 at 7:19 pm
save and close a file in VI
hit ESC
type :
type x
[ESC:X]