A glue record associates ("glue together") hostname (nameserver, or DNS ) with an IP address at the registry. These DNS records are created at the domain's registrar and provides a complete answer when the TLD nameserver returns a reference for an authoritative nameserver for a domain.
When a DNS resolver queries a nameserver for a domain, it needs the IP address of that nameserver to complete the request. However, if the nameserver's information is stored within the same domain, a circular dependency occurs, leading to an infinite loop. Glue records resolve this issue by associating the hostname of the nameserver directly with its IP address at the registry level. This preempts the need for additional DNS lookups, streamlining the resolution process.
There are some special requirements applied for certain TLDs such as .de, .be, .fr, .re, and some others as well. According to their registries, the name servers of the domain at the registrar must match the NS records in the DNS Zone.
The requirements for those top level domains come with some specific rules when it comes to their Glue Records. The configuration is very similar to the other TLDs, but with one major difference - instead of adding them from the Child name servers tab, you add them from the Name servers tab.
To do that, you need to follow these steps:
1. Navigate to your domain name's management page.
2. Go to the Name servers tab.
3. Once there, add your own named DNS server and the IP of our DNS servers, with space between them. Sample of such kind of configuration for a .de domain can be seen below:
Nameserver 1: ns1.your-domain.de 185.136.96.96
Nameserver 2: ns2.your-domain.de 185.136.97.96
Nameserver 3: ns3.your-domain.de 185.136.98.96
Nameserver 4: ns4.your-domain.de 185.136.99.96
Note: You should use the IP addresses listed on the right of your Dashboard. In the article, we are using example IP's.
Glue Records are not just technical DNS components; they are also essential for DNS Branding, which encompasses concepts like Vanity Name Servers and White-Label DNS. DNS Branding allows organizations to maintain a consistent and branded online presence while utilizing third-party DNS services.
If glue records are set up incorrectly, your domain’s DNS resolution can fail entirely. This happens because resolvers are unable to find the correct IP addresses for your nameservers, resulting in "Server Not Found" errors for visitors. The issue is particularly severe when your nameservers are hosted within the same domain, as this creates a circular dependency that DNS systems cannot resolve. To avoid downtime and ensure your website remains accessible, it’s essential to verify glue records for accuracy during setup and make adjustments promptly if needed.
If you encounter issues related to glue records, consider the following troubleshooting steps:
Question: What happens if I don't set up glue records?
Answer: Without glue records, you risk creating a circular dependency, leading to DNS resolution failure for your domain.
Question: How long does it take for changes to glue records to propagate?
Answer: DNS propagation can take anywhere from a few minutes to 48 hours, depending on various factors like Time-To-Live (TTL) settings and DNS cache.
Question: Are glue records mandatory for every domain?
Answer: While not universally mandatory, glue records are essential for domains that have nameservers on the same domain. For example, if your nameservers are ns1.example.com and ns2.example.com for the domain example.com, glue records are needed.