What is a non authoritative answer?
What is a non authoritative answer?
Non-authoritative answer simply means the answer is not fetched from the authoritative DNS server for the queried domain name.
What is a non authoritative response in DNS?
Non-authoritative name servers do not contain the original zone files. They may have a cache with previously requested DNS records from all the DNS lookups done previously. If a DNS server responded to a DNS query that doesn’t have the zone file, it is a Non-authoritative answer.
What is a non authoritative RR?
Non authoritative servers do not contain copies of any domains. Instead they have a cache file that is constructed from all the DNS lookups it has performed in the past for which it has gotten an authoritative response. Most often, a non-authoritative server answers with a previous lookup from its lookup cache.
What is an authoritative answer?
An authoritative answer is when the DNS server hosting the primary copy of the DNS record responses to your lookup. See the example below on how to get an authoritative response. The reason why the primary authoritative server isn’t involved in responding to all nslookup queries is to reduce server load.
How do I find my authoritative DNS?
To find out who is responsible for DNS hosting of a domain, you need to find the authoritative DNS servers (or Name Servers) for that domain. A list of DNS servers authoritative for the domain is shown in the Name Server (NS) record. To find this record, you can use the NSLOOKUP tool.
What is the difference between authoritative and recursive DNS?
There are two types of DNS servers: authoritative and recursive. Authoritative nameservers are like the phone book company that publishes multiple phone books, one per region. Recursive DNS servers are like someone who uses a phone book to look up the number to contact a person or company.
What are the three 3 types of DNS queries?
There are three types of queries in the DNS system:
- Recursive Query.
- Iterative Query.
- Non-Recursive Query.
- DNS Resolver.
- DNS Root Server.
- Authoritative DNS Server.
What are the two types of DNS message?
The DNS protocol uses two types of DNS messages, queries and replies; both have the same format. Each message consists of a header and four sections: question, answer, authority, and an additional space. A header field (flags) controls the content of these four sections.
What’s the difference between authoritative and non-authoritative answers?
An authoritative answer comes from a Nameserver (NS) that is considered authoritative for the domain which it’s returning a record for (one of the nameservers in the list for the domain you did a lookup on). A non-authoritative answer comes from anywhere else (a nameserver not in the list for the domain you did a lookup on).
Where does a non-authoritative answer come from in nslookup?
A non-authoritative answer comes from anywhere else (a nameserver not in the list for the domain you did a lookup on). If I perform a nslookup of google.com, I would get a response from one of my configured nameservers. (Either from my ISP, or my domain.)
What is the meaning of the non-authoritative DNS answer?
Whenever you query a DNS record on your local DNS server, it returns a non-authoritative (unofficial) answer. If you want an authoritative answer, you must explicitly specify the authoritative DNS server when you use nslookup or other utilities. I think a local DNS server should be called caching DNS server.
How does a name server indicate it is authoritative?
A name server indicates that its response is authoritative by setting the Authoritative Answer (AA) bit in the response to a query on a name for which it is authoritative. Name servers providing answers for which they are not authoritative (for example, name servers for parent zones), do not set the AA bit.