This page allows you to configure access control for your administration server. It allows you to:
You can enter a wildcard pattern of hosts that you wish to allow. You have the choice of restricting access by hostname, or by IP address. Restricting by hostname is more flexible - if a machine's IP address changes, you won't have to update your server. But on the other hand, restricting by IP address is more reliable - if a DNS lookup fails for a connected client, hostname restriction cannot be used.
If you think you might have problems with DNS, you should probably use IP address restriction. If not, you can probably use hostname restriction. You can also change the user name your server uses to verify that you are in fact the server administrator. This user name is the name you gave when you accessed the server manager for the very first time - your browser should have shown you a dialog box that said "Server Administrator", and you entered a username and a password to authenticate yourself. This name is an HTTP user name, so it is only useable within the server. Simply choosing a name and entering it here will cause the server to create the user for you. The authentication password is the password you give the server after you enter the authentication username you listed above.
Note that if you leave this password blank, the admin password will remain unchanged (as opposed to being removed.)