Unix Network Admin   «Prev  Next»

Viewing MX records - Exercise

Objective: Use nslookup to view MX records.
This exercise uses a Java applet to simulate a UNIX command line and allows you to practice entering commands. If you do not have Java active in your browser or are behind a firewall that does not allow Java applets, you will not be able to complete this exercise. If you do not see the applet below, click the Submit Button to review the solution to the exercise and continue with the course.

Exercise scoring

This exercise is not scored. When you have completed the exercise, click the Submit button to review the solution and continue with the course.

Instructions

In this exercise, you will use the nslookup program to view MX records. Start the simulation below and work through the situation presented.
1) View MX 1 2) View MX 2 3) View MX 3
  1. You are logged on as user1 and are in the /home/user1 directory. Issue a command that will open the proper program to view MX records
  2. View MX records
  3. Type nslookup. This will allow you to view Resource Records.
  4. nslookup
  5. Set |||(S7)nslookup to search for MX records
  6. Look up MX records
  7. set type=MX
  8. (S0)To look up MX records, rather than SOA, A, or CNAME entries, type set type=MX
  1. List the MX entries for the corporation.com domain
  2. List the MX entries
  3. corporation.com
  4. Type corporation.com to list all of the MX entries for that domain.
  5. Notice that your domain has two MX entries. Also, notice that the first entry has priority due to its lower number. Now, use nslookup to view additional MX entries. Look at acmetraining's MX setup.
  6. List the MX entries
  7. acmetraining.com
  8. Type acmetraining.com to view its MX entries. You may think that you should enter www.acmetraining.com, but you are searching for domain information, not for a specific host named www. Domains cannot have a name beginning with www.