Nslookup.exe is a Windows command-line administrative tool for testing and troubleshooting DNS servers. For starting the command line console, press START+R, write "cmd", and press Enter.
Nslookup.exe can be run in two modes: interactive and noninteractive. Noninteractive mode is useful when only a single piece of data needs to be returned. The syntax for noninteractive mode is:
nslookup [-option] [hostname] [server]
To start nslookup.exe in interactive mode, simply type "nslookup" at the command prompt:
C:\> nslookup Default Server: nameserver1.domain.com Address: 10.0.0.1 >
Typing "help" or "?" at the command prompt will generate a list of available commands. Anything typed at the command prompt that is not recognized as a valid command is assumed to be a host name and an attempt is made to resolve it using the default server. To interrupt interactive commands, press CTRL+C. To exit interactive mode and return to the command prompt, type "exit"" at the command prompt.
The following is the help output and contains the complete list of options:
Commands: (identifiers are shown in uppercase,  means optional) NAME - print info about the host/domain NAME using default server NAME1 NAME2 - as above, but use NAME2 as server help or ? - print info on common commands set OPTION - set an option all - print options, current server and host [no]debug - print debugging information [no]d2 - print exhaustive debugging information [no]defname - append domain name to each query [no]recurse - ask for recursive answer to query [no]search - use domain search list [no]vc - 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,AAAA,A+AAAA,ANY,CNAME,MX,NS,PTR,SOA,SRV) querytype=X - same as type class=X - set query class (ex. IN (Internet), ANY) [no]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 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 RFC record type (ex. A,CNAME,MX,NS,PTR etc.) view FILE - sort an 'ls' output file and view it with pg exit - exit the program
To check an A record for the naked domain, type:
To check a subdomain (A or CNAME records), type:
To look up different data types within the domain name space, use the set type or set q[uerytype] command at the command prompt. For example, to query for the mail exchanger data, type the following:
C:\>nslookup Default Server: ns1.domain.com Address: 10.0.0.1 > set q=mx > mailhost Server: ns1.domain.com Address: 10.0.0.1 mailhost.domain.com MX preference = 0, mail exchanger = mailhost.domain.com mailhost.domain.com internet address = 10.0.0.5 >
To query another name server directly, add the DNS server name to command line:
C:\>nslookup dnsazure.com ns1.durabledns.com Server: UnKnown Address: 184.108.40.206 Name: dnsazure.com Address: 220.127.116.11 C:\>