The default port of SSH is 22. To secure SSH more we need to change the port . This blog helps you how to change default SSH port on Ubuntu servers.
1. Switch as root user
$sudo su –
[sudo] password for user:
2. Open ssh configuration file
3. Change the line (Here changed the port to 5011).
4. Restart SSH service
After changing the default port you should specify the port while connect to remote system using SSH client
#ssh firstname.lastname@example.org -p 5011
Note : Before selecting the port please make sure that port is not using by any other services. You can verify this on /etc/services file.