Nslookup

Nslookup command to troubleshoot DNS issues.

Nslookup is a command line administrative tool that displays information which you can use to diagnose Domain Name System (DNS) infrastructure.

Syntax

Nslookup

Domain Name Display information about the host/domain NAME using default server
Domain_Name DNS As above, use DNS as server
help or ? Display information on common commands
Set OPTIONS 
All Display current server and host details
debug Display debugging information
nod2 Display exhaustive debugging information
defname append domain name to each query
recurse ask for recursive answer to query
search use domain search list
novc always use a virtual circuit
domain=NAME set default domain name to NAME
srchlist=N1[/N2/…/N6] set domain to N1 and search list to N1,N2, etc.
root=NAME set root server to NAME
retry=X set number of retries to X
timeout=X set initial time-out interval to X seconds
Type=X Set query type (ex. A,ANY,CNAME,MX,NS,PTR,SOA,SRV)
queryType=X same as type
class=X set query class (ex. IN (Internet), ANY)
msxfr use MS fast zone transfer
ixfrver=X current version to use in IXFR transfer request
server NAME set default server to NAME, using current default server
lserver NAME set default server to NAME, using initial server
finger [USER] finger the optional NAME at the current default host
root set current default server to the root
ls [opt] DOMAIN [> FILE] list addresses in DOMAIN (optional: output to FILE)
-a list canonical names and aliases
-d list all records
-t type list records of the given type (e.g. A,CNAME,MX,NS,PTR etc.)
view FILE sort an ‘ls’ output file and view it with pg
exit exit the program

Note

  • If ComputerToFind is an IP address and the query is for an A or PTR resource record type, the name of the computer is returned. If ComputerToFind is a name and does not have a trailing period, the default DNS domain name is appended to the name. This behavior depends on the state of the following set subcommands: domainsrchlistdefname, and search.
  • If you type a hyphen (-) instead of ComputerToFind, the command prompt changes to nslookup interactive mode.
  • The command-line length must be less than 256 characters.
  • Nslookup has two modes: interactive and noninteractive.

If you need to look up only a single piece of data, use noninteractive mode. For the first parameter, type the name or IP address of the computer that you want to look up. For the second parameter, type the name or IP address of a DNS name server. If you omit the second argument, nslookup uses the default DNS name server.

If you need to look up more than one piece of data, you can use interactive mode. Type a hyphen (-) for the first parameter and the name or IP address of a DNS name server for the second parameter. Or, omit both parameters and nslookup uses the default DNS name server. Following are some tips about working in interactive mode:

    • To interrupt interactive commands at any time, press CTRL+B.
    • To exit, type exit.

Example:

Nslookup Domain_Name

Display All details of Domain_Name
Nslookup
Set type = all
Domain_Name