nslookup {IPv4 | IPv6} hostname


Displays the IP address of the requested host.

Syntax Description

IPv4 Lookup only IPv4 address(es).
IPV6 Lookup only IPv6 address(es).
hostname Specifies the hostname.


Lookup both IPv4 and IPv6 addresses.

Usage Guidelines

For nslookup to work, you must configure the DNS client, and the switch must be able to reach the DNS server.

By default, the command looks for both IPv4 and IPv6 addresses and reports an error only when neither an IPv4 address nor an IPv6 address is found for the host.

If the IPv4 or IPv6 option is specified, DNS lookup happens only for that address type, and an error is reported when no address of that type is found.

Host Name and Remote IP Address Character Restrictions

This section provides information about the characters supported by the switch for host names and remote IP addresses.

When specifying a host name or remote IP address, the switch permits only the following characters:
  • Alphabetical letters, upper case and lower case (A-Z, a-z).
  • Numerals (0-9).
  • Period ( . ).
  • Dash ( - ) Permitted only for host names.
  • Underscore ( _ ) Permitted only for host names.
  • Colon ( : ).

When naming or configuring an IP address for your network server, remember the requirements listed above.


The following command looks up the IP addresses of a computer with the name myhost.mydomain that has 2 IPv4 addresses and 1 IPv6 address:

nslookup myhost.mydomain

The following is sample output from the command on a switch:

Host "myhost.mydomain" has the IPv4 address
Host "myhost.mydomain" has the IPv4 address
Host "myhost.mydomain" has the IPv6 address 2000::1


This command was first available in ExtremeXOS 10.1.

Support for using an IP address to obtain the name of the host was added in ExtremeXOS 11.0. Support for looking up IPv6 addresses was added in ExtremeXOS 12.4.

Platform Availability

This command is available on ExtremeSwitching X435, X440-G2, X450-G2, X460-G2, X465, X590, X620, X670-G2, X690, X695, X870, 5320, 5420, and 5520 series switches.