Important Information About DNS Flag Day

The Domain Name System is currently slow and inefficient. To address these issues, a number of DNS providers and DNS software vendors have agreed to remove workarounds for non-compliant DNS implementations on 02/01/2019. This change will make most DNS operations slightly more efficient. Furthermore, this measure enables operators to provide new functions, such as mechanisms to protect against DDoS attacks.

This action will affect non-compliant, authoritative servers that do not comply with the DNS standard RFC1035 and the EDNS standards RFC2671 and RFC6891. Websites hosted on incompatible authoritative servers may no longer be accessible due to the updated DNS resolvers.

Are the 1&1 IONOS DNS servers, zones, and firewalls EDNS compliant?

Yes, the DNS servers, zones, and firewalls of 1&1 IONOS are EDNS compliant.

How can I check my domain(s)?

You can check your domain at the URL below. Enter the desired domain name in the Online Tool. This can be found at the following URL:

https://dnsflagday.net

In which cases are there no needs for action?

In the following cases, you do not need to do anything else:

  • You have set up a domain at 1&1 IONOS and use the name servers of 1&1 IONOS.

  • You have set up an external domain at 1&1 IONOS and are using the name servers of 1&1 IONOS.

In which cases are there needs for action?

Further steps are required in the following cases:

  • You have set up a domain at 1&1 IONOS and are using external, non-compliant DNS servers from a third-party provider. In this case, contact the third-party provider or use the 1&1 IONOS name servers.

  • You have set up an external domain at 1&1 IONOS and are using external, non-compliant DNS servers from a third party provider. In this case, contact the third-party provider or use the 1&1 IONOS name servers.

  • You have an IONOS server on which a non-compliant DNS server is configured. In this case, make sure that the DNS software is updated and then check your domain(s) with the Online Tool.