Set up a custom domain at 1&1
1&1 has been part of the IONOS group since 2018. If you are logged in there, you may land in the IONOS control center — then follow the IONOS guide.
1&1 and IONOS both belong to United Internet. Some older 1&1 customers still see the old control center, newer ones were migrated to IONOS. If your login lands on login.ionos.de: follow the IONOS guide.
Step by step (classic 1&1 control center)
Login
Go to login.1und1.de and sign in. If you are automatically redirected to IONOS, follow the IONOS guide.
Open the Domain Center
In the control center: "Domains" → "Domain Center".
Domain DNS management
Click the domain, then "DNS settings". In the new screen: "Add DNS entry".
Enter the CNAME record
| Typ | CNAME |
| Name / Host | www |
| Wert / Ziel | cname.sosta.app |
| TTL | 3600 |
Apex via domain forwarding
Like IONOS, 1&1 does not support CNAME on the apex. Use domain forwarding from deinhaus.de to www.deinhaus.de, then CNAME on www.
Save, verify
Click "Apply". Usually 30–90 minutes until propagated. Then verify in Sosta under Website → Settings.