DNS Referrals

The term referral indicates a response to a query which does not contain an answer section (it is empty) but which contains one or more authoritative name servers (in the Domain Authority section) that are closer to the required query question. The response will typically (always from the root and TLD servers) contain in the Additional Information section the IP addresses (the A or glue records) of the supplied servers. A query to the root-servers for the IP of fred.example.com will result in the following DNS transactions:

1. Root-server returns a referral to the gTLD servers for .com with a list of server names in the Authority section and IP addresses in Additional Information section of response.

2. gTLD server returns a referral to the name servers for example.com with a list of server names in the Authority section and IP addresses in Additional Information section of response.