Linux modify SSH port and iptables firewall configuration

Linux Modify SSH Port 22

The code is as follows	Copy Code
Vi/etc/ssh/ssh_config Vi/etc/ssh/sshd_config

Then change to port 8888

As Root service sshd restart (Redhat AS3)

Using putty, Port 8888

Linux under the default SSH port is 22, for security reasons, now modify the SSH port is 1433, modify the method as follows:

The code is as follows	Copy Code
/usr/sbin/sshd-p 1433

First modify the configuration file

The code is as follows	Copy Code
Vi/etc/ssh/sshd_config

Find #port 221, here is the identity default use 22 port, modified to the following:

The code is as follows	Copy Code
Port 22 Port 50000

And then save the exit

Perform/etc/init.d/sshd restart

This way the SSH port will work concurrently with 22 and 50000.

Modify iptables configuration file: Vi/etc/sysconfig/iptables Add the following:

The code is as follows	Copy Code
-A rh-firewall-1-input-m state--state new-m tcp-p TCP--dport 80-j ACCEPT -A rh-firewall-1-input-m state--state new-m tcp-p TCP--dport 22-j ACCEPT -A rh-firewall-1-input-m state--state new-m tcp-p TCP--dport 50000-j ACCEPT

Restart the Iptalbes service:

The code is as follows	Copy Code
Service Iptables Restart

Now, use the SSH tool to connect to port 50000 to test for success.
If the connection succeeds, edit the Sshd_config settings again and delete the Port22 inside.

Set to two ports, the test is successful and then close a port, is the way in the process of modifying the Conf,
In the event of a drop, disconnection, misoperation and other unknown circumstances, but also through another port connection up debugging
In order to avoid the connection must send someone to the computer room, causing problems more complicated trouble.

Of course, you can also directly turn off the firewall (not recommended):
Effective after reboot

The code is as follows	Copy Code
Open: Chkconfig iptables on Close: Chkconfig iptables off

Immediate effect, reboot disabled

The code is as follows	Copy Code
Open: Service iptables start OFF: Service iptables stop