Check DNS records on Windows with nslookup
Last updated on: 2019-01-08
Authored by: Rackspace Support
There are many reasons why you might need to check the status of your Domain Name System (DNS) records. For example, you might need to verify that updates are correct or troubleshoot issues with accessing a service.
If you’re a Cloud DNS user, you can
view your DNS records through the Cloud Control
Panel. In addition, Microsoft® Windows®
nslookup, a built-in tool for checking your DNS records from the
nslookup, open a command prompt window by selecting Start >
All Programs > Accessories > Command Prompt.
Check a DNS record
To check a specific DNS record, you need to specify the
an optional record type (for example,
TXT), and the host name
that you want to check.
Note: If you omit the record type, it defaults to
The following example shows how to check
A records for rackspace.co.uk:
C:\Users\Administrator>nslookup rackspace.co.uk Server: cachens1.lon.rackspace.com> Address: 126.96.36.199 Non-authoritative answer: Name: rackspace.co.uk Address: 188.8.131.52
The first two lines of output specify the server to which the request was directed. This server is the default server that your system uses for DNS name resolution.
The second section gives the name of the record and the corresponding Internet Protocol (IP) address. However, the answer in this section is non-authoritative because it originates from a server (cachens1.lon.rackspace.com) that isn’t the root source for those records.
Get an authoritative answer
To get an authoritative answer you need to specify the authoritative (primary) name server at the end of the request.
-type=soa option to tell
nslookup to display the
authoritative name server, as shown in the following example:
C:\Users\Administrator>nslookup -type=soa rackspace.co.uk Server: cachens1.lon.rackspace.com> Address: 184.108.40.206 Non-authoritative answer: rackspace.co.uk primary name server = ns.rackspace.com responsible mail addr = hostmaster.rackspace.com serial = 1415913000 refresh = 3600 (1 hour) retry = 300 (5 mins) expire = 1814400 (21 days) default TTL = 300 (5 mins) ns.rackspace.com internet address = 220.127.116.11
The address labeled
primary name server is the DNS authority for the
If you add the address of the authoritative name server (ns.rackspace.com) to the first command, the record is now checked against that name server.
C:\Users\Administrator>nslookup rackspace.co.uk ns.rackspace.com Server: ns.rackspace.com Address: 18.104.22.168 Name: rackspace.co.uk Address: 22.214.171.124
Check when a cached record expires
DNS uses caching, which reduces the load on authoritative name servers. However, as a result, records might be outdated. If the authoritative and non-authoritative answers differ, you have a cached response from the resolver name server that you’re using. The length of time that a record is cached depends on its time-to-live (TTL) value. The TTL is a number that is specified in seconds.
To see how long a record is cached, include the
debug option, as shown in
the following example:
C:\Users\Administrator>nslookup -debug rackspace.co.uk ------------ Got answer: HEADER: opcode = QUERY, id = 1, rcode = NOERROR header flags: response, want recursion, recursion avail. questions = 1, answers = 1, authority records = 2, additional = 2 QUESTIONS: 126.96.36.199.in-addr.arpa, type = PTR, class = IN ANSWERS: -> 188.8.131.52.in-addr.arpa name = cachens1.lon.rackspace.com ttl = 2466 (41 mins 6 secs) AUTHORITY RECORDS: -> 151.138.83.in-addr.arpa nameserver = ns2.rackspace.com ttl = 2466 (41 mins 6 secs) -> 151.138.83.in-addr.arpa nameserver = ns.rackspace.com ttl = 2466 (41 mins 6 secs) ADDITIONAL RECORDS: -> ns.rackspace.com internet address = 184.108.40.206 ttl = 12982 (3 hours 36 mins 22 secs) -> ns2.rackspace.com internet address = 220.127.116.11 ttl = 12985 (3 hours 36 mins 25 secs) ------------ Server: cachens1.lon.rackspace.com Address: 18.104.22.168 ------------ Got answer: HEADER: opcode = QUERY, id = 2, rcode = NOERROR header flags: response, want recursion, recursion avail. questions = 1, answers = 1, authority records = 2, additional = 2 QUESTIONS: rackspace.co.uk, type = A, class = IN ANSWERS: -> rackspace.co.uk internet address = 22.214.171.124 ttl = 279 (4 mins 39 secs) AUTHORITY RECORDS: -> rackspace.co.uk nameserver = ns.rackspace.com ttl = 17465 (4 hours 51 mins 5 secs) -> rackspace.co.uk nameserver = ns2.rackspace.com ttl = 17465 (4 hours 51 mins 5 secs) ADDITIONAL RECORDS: -> ns.rackspace.com internet address = 126.96.36.199 ttl = 15754 (4 hours 22 mins 34 secs) -> ns2.rackspace.com internet address = 188.8.131.52 ttl = 15727 (4 hours 22 mins 7 secs) ------------ Non-authoritative answer: Name: rackspace.co.uk Address: 184.108.40.206
The response includes the following information:
- The first
Got answersection of this example is used to get the host name of the server from which you are requesting the
Arecord. In this example, the host name is cachens1.lon.rackspace.com.
- The second
Got answersection relates to your actual request.
HEADERsection contains details about the type of request and its success.
QUESTIONSsection shows that the request was for
Arecords for rackspace.co.uk.
ANSWERSsection displays one record with an IP address of 220.127.116.11 and a TTL of 279 seconds (4 minutes 39 seconds).
AUTHORITY RECORDSsection specifies the name servers that correspond to the domain.
ADDITIONAL RECORDSsection lists
Arecords for the name servers that are listed in the authority records section.
This response shows that the name server that the client computer uses will
reuse the same
A record for rackspace.co.uk for the next 4 minutes and 39
seconds. If you run the same command on the authoritative name server, you
see the current maximum TTL for the record.