Glue Records (associated DNS)
They are the entries that are to be created in the registry (the company which manages a TLD) for a domain can act as a DNS server.
We will give a practical example to understand better this operation. We have registered the domain example.com and we want to use it as a DNS server to create ns1.example.com y ns2.example.com.
The problem with this is that by the way the DNS works, every time someone tries to access example.com, it have to consult with one of the subdomains (ns1.example.com o ns2.example.com) to resolve this direction, but they are both of your domain. Since you can not reach a subdomain before reaching the domain and the domain is what you're looking for in the first place, it seems that we are trapped. We will embody the process to find the right direction:
- P: "I'm trying to find www.example.com. ¿What is the IP address?"
- R: "I have no direction. Looking for DNS servers for this domain."
- P: "OK example.com. What are your DNS servers?"
- R: "ns1.example.com"
- P: "Ok. What is the IP direction of ns1.example.com?"
- R: "I don't have the direction. ns1.example.com is a subdomain of example.com. Search the DNS servers for this domain."
- P: "Ok. What is the DNS server for example.com?"
- R: "ns1.example.com"
- P: "Argh! You just indicated this direction. What can I do?"
Here is the problem! If the host "ns1.example.com" belongs to the domain that we are looking for, how can we resolve the IP?
The solution are Glue Records. In this way, the registry creates "A" entries in his servers to el registry crea entradas "A" to attempt to resolve ns1.example.com so we can obtain his IP.
It looks complicated, but it is actually very simple. In addition to creating them in our system is also very simple.
IMPORTANT: Although the Glue Records are created you have also to create A entries to the respective IP hosts(ns1.example.com y ns2.example.com) in the DNS zone.
How to create a Glue Record?
- Access to My domains.
- Click on the link Manage of the domain.
- Click on the tab Glue Records and there the button Manage.
- Introduce the DNS server and his IP.
- Click on Create. You already have the Glue Record created. From there you can also edit or delete your IP if necessary in the future.