I’m writing this notes for whom would like to setup a dx cluster and he owns a not much stable ddns.
As you should know, if you setup you server for hosting a dxcluster you also need to share with the other cluster the address of your server and the service port.
Usually it is possible to sign at a public ddns service for obtaining a name connected to the actual server IP. This in most of case happens because you do not have a static IP address for your server.
So after signing to a ddns service (a free one) you can discover that they are in most of case very unstable. Not always but often.
I discovered a free ddns (afraid.org) that is quite reliable and easy to implement in a linux environment (using ddclient for example).
But after couple of month I discovered that the domain I choose died for some reason.
It is a not a big problem to restore, just change a configuration on the site and on your linux machine and you start it again.
But what happen if you linked to the previous dns name some service? In case of dx cluster you must resubmit the form here (www.dxcluster.info/telnet/submit.php).
I have this website hosted and the domain name registered, I decided to create an alias for the telnet dxcluster service using this registered domain name.
In the majority of hosted domain service you can access to the DNS records setup.
You don’t need to alter nothing there. You just need to decide a subdomain name to put instead of www and add a CNAME record ( google “how to add a cname record” and you can see a lot of useful information)
In my case: I have a free registered ddns service iz0tws.strangled.net and the dxcluster, so I just added this cname record:
dxcluster CNAME .iz0tws.strangled.net
this allow me to aliasing the iz0tws.strangled.net as dxcluster.iz0tws.com
So if you verify the ip of dxcluster.iz0tws.com you obtain the ip address of iz0tws.strangled.net
Next time I will switch for some reason the ddns domain name I need to reconfigure only the setup of linux server and not of all the pointers to it.
IZ0TWS-2 dxcluster.iz0tws.com port 7300
Update april 2020: Due to a very few spare time for managing my dxcluster station I decided to quit. So the previous address is not anymore active and delisted by the cluster list. I decided to keep the article visible for future reference, but nothing will work anymore.