Ddns for AirPort Extreme

or how configuration AirPort Extrem with ddns services.

To configure the AirPort Extreme for DDNS service you will need to use the AirPort Utility, as follows:

• Run the AirPort Utility, select the Extreme base station, and then, select Edit.
• Click on Internet > Internet Options...
• Use dynamic global hostname (checked)
• Hostname: <Enter your DDNS provider's domain name here. For example, if you are using DynDNS, enter: dyndns.com>
• User: <Enter your DDNS user account name here.>
• Password: <Enter your DDNS user account's password here.>
• Click on "Save."
• Click on "Update."
• Allow the Extreme to restart.

... as far as free, you already know about No-IP, another would be Duck DNS. To find others, just do an Internet search for "free DDNS."

Another problem I do not understand how to open the port to access the USB disk connected to an AirPort Extreme, if I have to use ip the airport.

FWIW. When you have a different issue, you should start another post.

However, to help answer your question, please check out the following AirPort User Tip.

Do you know a ddns free compatible AirPort Extreme?

I already provided you that answer in my earlier reply.

Last weekend I tried with different ddns's services. All work but only with the port vpn, with other ports ftp, ssh, http, https and apt not work. With the other router I was using until a few days ago I never had these problems.

There are no service options (ftp, ssh, http, etc.) related to DNS - DNS does nothing more than map a name to an IP address. The fact that your VPN works tells me that the (free) DDNS service is working - you can map your DNS name to your IP address.

Services are a whole different issue. The base station will, by default, block incoming connections. You need to enable port forwarding (in the Network tab of Airport Utility) to tell the base station to allow other protocols into your network. Again, this has nothing to do with the DNS service.