Configure Dynamic DNS in your FritzBox! router

Dynamic DNS wihtin is free of charge.
Dynamic DNS points a hostname to a dynamic IP. This allows you to join your home network from the internet even if your public IP is assigned dynamically. 
To setup dynamic DNS: 
First, connect to your DNS-Stock account and add a dynamic DNS record to the DNS zone of your domain with the hostname you want (DNS section -> list Dynamic DNS records) , 
ex.: for you add an A record pointing to with the hostname athome.
You will be asked to define a login and a password: This allows you to create new separate credentials only for the dynamic DNS updates.
Now enter the config menu of your router and configure as follow:
Dynamic DNS provider : User-defined
Update-URL :<domain>&username=<username>&password=<pass>&myip=<ipaddr>
Domainname: yourhost.yourdomain.tld (
Username: the username you defined when you created the dynamic DNS entry
Password: the password you defined when you created the dynamic DNS entry
The values passed to the different query string variables in the update-url (<domain>, <username>, <pass>, <ipaddr>) come from your router.
Please read the manual of your router.