Dynamic Domain Name Service (DDNS) is not anything new from the last decade. It associates a domain name to an IP address that changes over time. Users could access to the resources behind a dynamic IP address assigned CPE with an easily memorized domain name instead.
In this post, I ll post the procedure of setting up DDNS at ScreenOS using NO-IP DDNS service with SSL enabled in GUI. One of ScreenOS’ beauties is the GUI management.

1.  Go to: “Network” -> “DNS” -> “DDNS”
2.  Check “Config DDNS Client” and “Enable DDNS Client” and click “Apply”
3.  Click “New” button to setup a DDNS service.
4.  Fill in the blanks and it should be
   1. For server type: “dyndns”
   2. Server name: “dynupdate.no-ip.com”
   3. Refresh Interval: “3”
   4. Minimum Update Interval: “60”
   5. Clear text: “uncheck” (unchecking this option makes the DDNS update via https)
   6. Username and Password: (input the one you have registered with at the NO-IP web site.)
   7. Agent: “we could let the ScreenOS to fill in itself”
   8. Bind to Interface: (select the WAN interface that is connecting to the internet.)
   9. Host Name: (host name is the DDNS name you have registered at NO-IP web site.)
   10. Service: “dyndns”
5.  Click “OK” after finished.
6.  In this case, it should not work with the following error because the geotrust cert needs to be installed.
7.  The Juniper web site has a guide of installing the Geotrust cert. The following URL from the official Juniper web page describes the procedure of the cert installation.ref: http://kb.juniper.net/InfoCenter/index?page=content&id=KB7380
   1. Download the cert: http://www.geotrust.com/resources/root_certificates/certificates/Equifax_Secure_Certificate_Authority_DER.cer
   2. install the cert at GUI:
      1. Go to “Object” -> “Certificates”
      2. click “Browse” to select the file.cer and click “Load”
   3. Once it is done, your Cert page should look like this.
8.  Now the DDNS update via HTTPS should update successfully with the “Last-response” of “Good” at “Network” -> “DNS” -> “DDNS” page.

To verify the DDNS with dynamic IP address association, logging back into the NO-IP website should have the record of the WAN IP address of the firewall bind to DDNS host address.