Posts Tagged ‘SSH’

SSH: short for Secure Shell, SSH (developed by SSH Communications Security Ltd.) is a secure protocol for remote logins. Using an SSH client, a user can connect to a server to transfer information in a more secure manner than other methods, such as telnet. Below is an example of how an SSH session, which uses a command line interface, may look. SSH defaults to port 22.

Modify the SSH remote login port to 9999

# vi /etc/ssh/sshd_config
Port 9999
# service sshd restart

Add a port to the firewall

The default iptables only open port 22 for ssh service, the use of additional ports such as 9999 need to add this port to a white list in iptables. If you don’t add this port, you will not connect to the SSH server.

# iptables -I INPUT -p tcp –dport 9999 -j ACCEPT
# iptables -A INPUT -p tcp –dport 9999 -j ACCEPT
#service iptables save

You need to save the command to the iptables configuration file

iptables-save >/etc/sysconfig/iptables