First off, let’s test ssh access:

host user $ ssh x.y.z.w
ssh: connect to host x.y.z.w port 22: Connection timed out
host user $ 

Let’s add ssh access. Go to Applications->System Settings->Security Level:

If you are not root, you will get a prompt to enter the root password:

Be default nothing is enabled as trusted. The Other ports (1029:tcp) is just an example, it is not already enabled. You can add other ports using this format to the box on the right:

To enable SSH, for instance, just check the box and click OK:

You will receive a warning about overwriting your existing config:

Click Yes if you want to do that. Note that you can view the configuration:

[usr-1@srv-1 ~]$ cat /etc/sysconfig/system-config-securitylevel
# Configuration file for system-config-securitylevel
--enabled
--port=22:tcp
[usr-1@srv-1 ~]$

No, it doesn’t work to simply edit this file. The GUI is pretty straightforward, just do that.