LAB 11-2: DNS and NSLOOKUP

Objective

Observe the function of DNS hierarchy and resolution using the nslookup command.

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Lab Steps

I. Basic nslookup Usage

1. Run nslookup:

   • If experiencing DNS request timed out errors:

     nslookup
     > server 8.8.8.8
     

2. Simple Query:

   nslookup www.champlain.edu
   

   • Output should display:
     • Address of the DNS server queried
     • IP address of the hostname

3. Interactive Mode:

   nslookup
   

   • You will see a > prompt.
   • Enter any hostname to resolve.

4. Query Name Server Records (NS):

   > set type=ns
   > champlain.edu.
   

5. Query ROOT Zone Servers:

   > .
   

6. Query TLD Servers:

   > edu.
   > com.
   > net.
   

   • Explore other TLDs from IANA Root Zone Database

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II. MX Records

1. Set type to MX:

   > set type=mx
   

2. Lookup the following domains:

   > hotmail.com
   > champlain.edu.
   > mymail.champlain.edu
   > gmail.com (or another domain you're familiar with)
   

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III. Querying Specific DNS Servers

1. Exit current session:

   > exit
   

2. Start new session with Google DNS:

   nslookup
   > server 8.8.8.8
   

3. Try a few hostname resolutions:

   > www.google.com
   > www.champlain.edu
   

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IV. Using Quad 9 DNS

1. Set server to Quad 9:

   nslookup
   > server 9.9.9.9
   

2. Resolve isitblocked.org:

   > isitblocked.org
   

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