Change the default port(22) SSh [CENTOS] - linux

Question

I am trying to change d default port (22) for my system, I edited the sshd_config file by changing to my desirable port no (5555) and restarted my service but it seem not to work . is there something else i have to change? thanks

Answer 1

Yes, you must allow that new port in iptables. iptables is the firewall program for Linux.
With root privileges you will need to do this:
iptables -I INPUT 1 -p tcp --dport 5555 -j ACCEPT
Make sure you can connect using port 5555 then disable the old port.
iptables -A INPUT -j DROP -p tcp --dport 22
then save the new settings
/etc/init.d/iptables save
Check out this really good webpage for more information:
http://www.rackspace.com/knowledge_center/article/introduction-to-iptables#Save_Save_Save_your_Ruleset

Answer 2

1) Make a backup of the sshd config file (optional but a good idea):
cp /etc/ssh/sshd_config /etc/ssh/sshd_config.bak
2) edit the sshd_config file to include your alternate port
vi /etc/ssh/sshd_config
Leave the default port 22 active for now and add your custom port
# Open ports for sshd
Port 22
Port 5555
3) Open the custom port in your firewall
iptables -I INPUT 1 -p tcp --dport 5555 -j ACCEPT
service iptables save
4) Use a new terminal window to make sure you can login with your custom port
ssh -p 5555 myuser#myserver.com
If this doesn't work, now you can still login on port 22 to troubleshoot
5) Once you've confirmed the custom port works, edit the sshd_config file and firewall settings to block port 22
vi /etc/ssh/sshd_config
...
# Open ports for sshd
# Port 22
Port 5555
...
iptables -A INPUT -j DROP -p tcp --dport 22
service iptables save
Now you'll want to test again to make sure you can login with your custom port but not with the default port of 22.
You will need to have root privileges or use sudo for the above commands.

Answer 3

Step - 1:
nano /etc/ssh/sshd_config
and change the port from 22 to the desired one i.e. 5555
service sshd restart
Step - 2:
nano /etc/sysconfig/iptables
Here, you will find an entry for port 22. You will need to change it to 5555
service iptables restart
Now, try the SSH using,
- ssh -p 5555 root#Your IP Address

Answer 4

To Change the SSH Port for Your Linux Server
Connect to your server via SSH
Switch to the root user
Run the following command:
vi /etc/ssh/sshd_config
Locate the following line: #Port 22
Remove # and change 22 to your desired port number like 2224 etc.
Restart the sshd service by running the following command:
service sshd restart