Nslookup
| Company type | Software utility |
|---|---|
| Industry | Network administration |
| Founded | 1986 |
| Founder | Andrew Cherenson |
| Products | DNS query tool |
nslookup—an abbreviation for name server lookup—is a network administration command-line tool designed to query the Domain Name System (DNS) for retrieving mappings between domain names and their corresponding IP addresses, as well as other types of DNS records.
Overview
This utility is included within the BIND name server suite. Developed by Andrew Cherenson as part of a UC Berkeley course project in 1986, nslookup was first distributed with the 4.3-Tahoe BSD release. Initially, the Internet Systems Consortium intended to phase out nslookup in favor of host and dig during the BIND 9 development cycle; however, this plan was reversed with the release of BIND 9.3 in 2004, and full support for nslookup has continued since then.
In contrast to dig, nslookup operates independently of the system’s native DNS resolver library, which can result in variations in its operation. Certain vendor implementations may integrate additional name sources such as host files or utilize services like Network Information Service. Furthermore, its performance can be affected by configurations specified in the resolv.conf file.
The Linux distribution of nslookup is based on Cherenson’s original BSD source code. The version available for ReactOS, created by Lucas Suggs, is distributed under the terms of the GPL.
Usage
nslookup offers both interactive and non-interactive modes. When launched without parameters or with particular flags, it enters interactive mode, enabling users to adjust settings or perform DNS queries at the nslookup prompt (>). If no arguments are provided, it queries the default DNS server. The use of a minus sign (-) allows execution of subcommands directly from the command line. In non-interactive mode, it conducts queries immediately based on command-line inputs using the default name server.
See also
- dig, a tool for querying DNS servers directly, commonly used in troubleshooting and network management.
- host, a straightforward utility for DNS resolution tasks.
- List of DNS record types, detailing various record categories stored and retrieved via DNS.
- Root name server, which are authoritative servers responsible for managing domain name resolution at the highest level.
- whois
- BIND name server
Further reading
External links
Microsoft Windows
- nslookup – available through the Microsoft TechNet library
- Using NSlookup.exe, from the Microsoft Knowledge Base
Unix-like OSs