When a name server tries to resolve the IP address of a host, like example.com, it must find the IP address from the name server for the host. If the name server for the host is a subdomain of the host itself, such as ns1.example.com, the lookup can result in a circular dependency. The first name server has to know the IP address of example.com to resolve the IP address of the name server, ns1.example.com, to find the address of example.com.
Glue records are a way to make the IP address of the name server known when it is a subdomain of the domain for which it serves. For example, if your domain is example.com and your name servers are ns1.example.com, ns2.example.com, ns3.example.com, and ns4.example.com, create four glue records linked to each name server of the IP address.
When to use glue records
Use glue records when you are hosting your own DNS name servers. Domain name registries often require glue records before allowing domains to use your name servers. And if your name servers are subdomains of the domain they are hosting, glue records are always required.
Setting up glue records
To set up glue records for a name server (such as ns1.example.com), first navigate to the parent domain name (example.com) in Google Domains.
- On the DNS tab , click on Global DNS Settings.
- Click on Manage glue records.
- If you want to use IPv4 or IPv6 in an existing record, click on the respective IPv option to add it, and then enter the desired address.
- To create a new record, click Create new record.
- Click Save.
Tip: To delete the glue records, click Delete . Make sure the host is not currently in use by this domain. Check the Name servers section within the DNS page.
Transferring in glue records
When you transfer in a domain that has glue records configured, Google Domains will try to create glue records. Check the glue record entries after you complete the transfer in process.
Unable to delete glue records
If you’re unable to delete or save changes to glue records, it may still be linked to the domain. Check the Name servers section within the DNS page and delete or change the name server record that contains the host you'd like to edit or delete.