Dynamic DNS

[#1]

I have an account with PlusNet and I can ping my router's WAN IP by pinging freddy.plus.com - assuming freddy is my account name (which it isn't!). I can manage my router and also get to IP Cameras by specifying a port http://freddy.plus.com:2002.
In the past I have had other usernames of various sites and they also work in the same way.
I now have a new account with plusnet and this function doesn't work with that account. When I try pinging freddy2.plus.com it comes back with an unknown destination.
So my query is where is this dns relationship between my IP address and the name freddy.plus.com specified? I guess it must be in PlusNet somewhere as I haven't got a dynamic dns set up anywhere - and it wouldn't provide me with that name anyway. Also my IP changes everytime I reboot the router so it must keep track of it. freddy.plus.com has worked ever since I set up the username back in 2001.
I do have a web site www.freddy.com but that is hosted at PlusNet - not on my own router's WAN port.
Any ideas anyone?
-Jerry
I have the PlusNet Technicolor fibre router at both locations.

[#2]

You need to go to a fixed IP which you can set up from here: https://portal.plus.net/AddOns.html It will cost you a £5 set up fee.
Alternatively you could go for a dynamic DNS service. You'd configure the router to sign in each time it connected so that it followed your IP changes.

[#3]

Thanks for your reply.
Are you saying that if I had a fixed IP from PlusNet then I would automatically be able to use freddy2.plus.com?
-Jerry

[#4]

I think it should be the default after you change to fixed IP, if not you will need to raise a ticket here: https://www.plus.net/wizard/?p=wizard&page=22425&wizard_id=38

[#5]

Thanks - yes you are right. All good now,
-Jerry