(Don’t use that number for anything; I have a dynamically-assigned address too.) This mapping isn’t always one-to-one, but for this discussion let’s pretend they are. MX records specify other computers that handle mail for a given domain.To continue the phone analogy: My primary MX is my home phone.Imagine if the phone company changed your number twice a day — people would have a hard time calling you.
For instance, as I write this, it matches the domain name “technopagan.org” to the number “24.2″.
We maintain the #1 list of Dynamic DNS (DDNS) providers online.
Dynamic DNS is a method that allows you to notify a Domain Name Server (DNS) to change in your active DNS configuration on a device such as a router or computer of its configured hostname and address.
(about 4.29e9, 4 billion or so) possible numeric addresses for the Internet in IPv4.
In practice, though, many of them were allocated in an inefficient manner a long time ago, in a way that can’t easily be undone today.