How to edit iptables in linux

Problem:
sometimes you may receive below error like

The description for Event ID ( 0 ) in Source ( sshd ) cannot be found. The local computer may not have the necessary registry information or message DLL files to display messages from a remote computer. You may be able to use the /AUXSOURCE= flag to retrieve this description; see Help and Support for details. The following information is part of the event: sshd: PID 2992: Accepted publickey for build from 10.69.250.31 port 33344 ssh2.

Solution :
Either Turn off the firewall in linux or add the port 22 as exception in iptables

To disable selinux  edit /etc/sysconfig/selinux    and set SELINUX to disabled.

SELINUX=disabled

I've encountered such problems when the binaries and libraries were not
executable by SYSTEM.
"chmod 755 /usr/sbin/* /usr/bin/*" fixed the problem.

If the problem still exists, add the port to the iptables.

For adding port 22 to the iptables, from shell run

iptables -A INPUT -p tcp --dport 22 -j ACCEPT

or

edit /etc/sysconfig/iptables
and append this line

-A INPUT -p tcp --dport 22 -j ACCEPT
Save and close the file. Restart iptables:
/etc/init.d/iptables restart
or
service iptables restart
Learn more about iptables by
man iptables