Question

The main use of nslookup is to help with any DNS issues you may have. You can use it to find the IP address of a host, find the domain name of an IP address, or find mail servers on a domain. This tool can be used in an interactive and a noninteractive mode. In Lab 1.3 , you'll use nslookup .

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LAB 1.3 : NSLOOKUP

1. Open a command prompt or a terminal window.
2. To work in interactive mode, type nslookup at the prompt and press Enter. You will get an nslookup prompt, as you see in Figure 1.4 . To escape the prompt, press Ctrl+C.

   

   Figure 1.4 : Using nslookup

3. To work in noninteractive mode, type nslookup www.example.com at the prompt to acquire DNS information for the specific site such as Figure 1.5 .

   

   Figure 1.5 : Using nslookup on a URL

4. Now try nslookup with one of the IP addresses displayed in your terminal window attributed to www.wiley.com . This will do a reverse lookup for the IP address and resolve to a domain name.
5. To find specific type assets, you can use nslookup –querytype=mx www.example.com . In Figure 1.6 , you see the result of using qureytype=mx .

   

   Figure 1.6 : Using nslookup with ‐querytype=mx

Instead of –querytype=mx , you can use any of the following:

HINFO	Specifies a computer's CPU and type of operating system
UNIFO	Specifies the user information
MB	Specifies a mailbox domain name
MG	Specifies an email group member
MX	Specifies the email server

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