In my good old days with LINUX I struggle quite a bit to understand what is a port number & how it works, what is firewall & why the hell it is blocking, etc. You have to understand port number when you work with tomcat server (remember server.xml 🙂 – man it sucks), it works in 8080 but not in 8090 or you name it, it just doesn’t work at all :-).
Today I think I should publish this tip, because if you are asking me about IPTABLES I will say it is a nightmare :-), any small mistake you do with it’s conf file then you are gone.
Generally iptables (firewall) stores its configuration in iptables file (/etc/sysconfig/iptables). You need to edit this file and add rules to open port number. You need a root credentials to execute the following steps.
Open the file:
Append rule as follows:
-A INPUT -m state –state NEW -m tcp -p tcp –dport port_number -j ACCEPT -make sure you change the port_number to actual number (8090 or 8088)
# /etc/init.d/iptables restart
Verify that port is open:
# netstat -tulpn | less
- Linux iptables an Introduction (brighthub.com)
- Managing Linux Firewalls with Iptables (brighthub.com)