Friend of mine are customer of ZIggo (a dutch provider), (no static external ip-address) and i am building a pimatic set for them.
It is intended that they oparate their pimatic via their smartphones.
The solution is a ddns.
Their router only allows ddns via dyndns.org. (40 euro a year)
This means that they have to manage their ddns via a pc. so i can use the free ddns from no-ip.
Not so energy friendly to have a pc running all day to manage your ddns.
I found a solution:.run ddns on your raspberry thats also running Pimatic.
I installed it as suggested. And it works.