The shorthand for Name Server Lookup is NSLOOKUP, and it allows you to query your DNS service. The program is often used to retrieve a domain name using your command line interface (CLI), receive IP address mapping information, and search DNS records. It can also be used to send email.
How does NSLOOKUP work? When you run NSLOOKUP, the local system queries its DNS server to find the IP address of a hostname or IP address. You can use NSLOOKUP to check the status of DNS servers or test whether your network configuration is working correctly. The -h parameter displays detailed help text on how to use NSLOOKUP.
Here are some examples of usage:
To look up the address of Google's DNS server, type nslookup -h at your terminal and press Enter. A list similar to what's shown below will appear. Notice that instead of entering the fully qualified domain name (FQDN) of google.com, I entered just google to see what would happen. The result is that NSLOOKUP returns a list of DNS servers at which Google provides its services.
Now let's say that I want to make sure that my current DNS server is working properly. To do this, I need to perform a lookup on myself!
The network administration command-line utility nslookup is available for a variety of computer operating systems. It is used to query the Domain Name System (DNS) for information about domain names or IP address mapping. - Wikipedia The primary purpose of nslookup is to troubleshoot DNS-related issues. Nslookup can be used interactively or in a non-interactive fashion. When used interactively, the user provides input to search for specified information.
To demonstrate the use of nslookup, we will do the following: 1. Determine a host's IP address. Two: Determine an IP address's domain name. 3. Identify mail servers for a domain. 4. Retrieve the address of any server identified in steps 2 or 3.
Here are the steps:
server 127.0.0.1(or some other valid DNS server).
Non-authoritative answer from cache of localhost.localdomain:
Address Type Address Type
www.apple.com A 220.127.116.11 Primary Host Name
Nslookup connects to a specified DNS server. You have the option of using a DNS server other than your primary DNS server. To do so, enter nslookup, followed by the name of the domain to be queried and the name or IP address of the DNS server to be used. For example: nslookup google.com 192.168.1.1.
NSD (for "name server daemon") is an open-source Domain Name System (DNS) server in Internet computing. The goal of this effort is to introduce diversity to the "gene pool" of DNS implementations utilized by higher level name servers, hence increasing DNS's resilience to software defects or exploitation.