Hmm, curious it should have worked in 2.7.2. What modem is that exactly? I have hit that before and handled it by feeding the init string to mpd5 that allows it: &F&C1&D2E0S0=0${temp} Try that.

@ddbnj Then I can only assume you didn't reboot pfsense. That's pretty much necessary to get the full sequence. Otherwise, you only get renewals.

yeah you need to create your key ;) Simple google for bind dynamic dns should get you going. Have not done it in years... But guess I could fire bind in pfsense and do a walk through... Pretty busy with getting back to work from holiday so not sure be able to get to until later.