The purpose of this tutorial, is to create understand around the term Glue Records when creating a delegation between a domain and a sub domain in window server operating system.
DNS Glue records are records that are added in a domain and sub domain to create a pointer from NON-Authoritative DNS server to Authoritative DNS server hosting the resources records.
The important of adding a Glue Records in zone, is because, when a client generate a DNS queries for host record in the sub domain and that queries is received in zone or domain and it is check against the resource records that they are hosted, if it cannot be resolved because they don’t have it in their DNS records, the Delegation and Glue Records that was added to the domain and zone will inform the zone that the record is in the sub domain configured in DNS server comput10.
I think a Glue record act as a referrer adviser to a zone or a domain that a received a DNS quarries of a host record for which is not authoritative.
There must be relation between zone, domain and sub domain for it to contiguous, for that reason we will use zone called google.com, domain called chrome.google.com and a sub domain name called users.chrome.google.com
From the illustration above, you can see that there are relationship between the zone, domain and the sub domain. The relationship is google.com and this has made it contiguous. Make sense? Let’s move on if you think it make sense
Now that you have a clue, we will configure a two DNS server, The zone and the domain will be configure in the first server (comput01) and the sub domain will be configure in the second DNS server (Comput10) . The sub domain will be configured to delegated authority for the server 2 (comput01).
The first DNS server will be called comput01 and zone that will be configure in the DNS server will called google.com.com and the domain will be called chrome.google.com.
The domain will delegate authority for the sub-domain called users.chrome.google.com hosted in the server named comput10
To create a delegation between the DNS server of the sub domain users.chrome.google.com and the DNS server domain chrome.google.com,
The Name Server (NS) of the sub domain need to be added to the DNS zone google.com to create a glue records. The sub domain Name Server and Host record that need to be added to the Zone configured in the Comput01 can be seen below.
- Name Server (NS) : users.chrome.google.com
- Host record (A, AAA) : comput10.users.chrome.google.com + IP address of the server
Also the Name Server (NS) of the domain chrome.google.com need to be added to sub domain users.chrome.google.com to create a glue record of the domain in the sub domain.
- Name Server (NS) : chrome.google.com
- Host record (A, AAA) : comput01. chrome.google.com + IP address of the server
This information is needed after the delegation has been configured between the domain and sub domain
Now we will use two DNS server to demonstrate how to create a glue records, but first we need to create a delegation between a domain and sub domain.
Server 1 (Comput01) Create a zone (google.com), domain (chrome.google.com) and edit Name Server for the zone and domain
- Configure a Zone see how- in our case we create google.com as zone in our DNS server comput01
- Add or edit the Name Server (NS) of the Zone that you have just created
- Create Reverse Lookup Zones for the zone that you have just created
- Create a Domain in the zone see how – in our case we create chrome as a domain in our Google zone in our DNS server comput01
- Add or Configured the Name Server (NS) of the chrome domain in the zone. in our case we create Name Server of Chrome in google.com zone
Server 2 (Comput10) Create a Sub domain and edit the Name Server for the Sub domain
- Create a Sub Domain in server 2 (comput10), see how. in our case we create a users.chrome.google.com
- Add or edit the Name Server (NS) of the Sub Domain, you have just created
- Create Reverse lookup Zones for the Sub Domain that you have just created
Server 1 (Comput01) – Creating delegation for the Sub Domain from the domain you created in the Comput01, see diagram and follow the step
- Create a delegation for the sub domain in the domain created in the server , see how , in our case we will right click the domain Chrome in the Google.com zone
- Click New Delegation
- Click next
- Type the child domain in the delegated item
- Click next
- Enter the FQDN of the sub domain, in our case we enter the comput10.users.chrome.google.com hosted in server 2 and the IP address of the server 2
- Click inside box , you see green, which indicate that you have successfully delegate the sub zone for the DNS server 1
- Click Ok
- Click next
- Click Ok or finish
Created a Glue Record of sub domain (users.chrome.google.com) in the Server 1 and Glue Record of domain (chrome.google.com) in DNS server 2
Server 1 (Comput01) Create a glue record of the sub domain in the zone and see diagram below.
- Create a Name Server and a host record of the sub domain in the Zone created in DNS server named comput01 using the IP address of the server in which the sub domain is created.
Repeat the same process in the DNS server hosting the sub domain by create a host record and Name Server of the delegated sub domain in DNS server named comput010 but using the IP address that hosted the delegated sub domain.
All you need to understand about creating a glue record is simple, just create a Name Server (NS) of the sub domain in the delegated domain verse versa.
Server 2 (Comput01) verify that the Glue records of the sub domain you have created in the DNS zone in server 2 (Comput01). You can also perform this verification in the sub domain DNS server (comput10)
After you have created the Name Server and the Host record of the sub domain in the zone created in server 1 (Comput01), it is time to verify that we have created a glue record in the zone and draw home once and for all what is Glue records when configuring delegation in window server.
To verify that the Glue records of the sub domain created in the DNS zone in Server 2 (Comput01) follow the step and see diagram below.
- Right click Name Server (NS) of the child domain created in the Zone
- Click properties
- Click on the child domain Name server that in the list
- Click remove
- Click apply
- A pop up window should show up,
- Examine the information because that is the glue records.
- Click Ok
Note that, we have click remove for the purpose of verifying that the glue record was created in the domain hosted in the DNS server comput01.
If you are configuring the DNS server in a production environment, you will have to recreate the glue records.
Note that when you create the glue record the green sign will not show and this does not mean is not properly configured.
Glue record must be confiogure beteen a the domain and the sub domain configure between the domain configured for thre delagaation
Remember that you must configured Sub Domain DNS TCP/IP with the IP address of the DNS server that hosted the domain, verse versa. This will normally be configured in the Alternative DNS IP address, while the preferred will be configure with their own IP address see what we mean.