From Dahua Wiki
Following the development of P2P and cloud service, Dahua is going to stop support for Dahua DDNS and Quick DDNS service on product firmware from 2017/7/30.
Device loaded Dahua/Quick DDNS service would be able to register and use the service until 2017/12/31. After 2017/12/31, devices haven’t registered on the DDNS server, won’t be able to register and use the Dahua/Quick DDNS service. Devices has register before 2017/12/31 would still be able to use the service.