Your computer sends a DNS request message to your local DNS server. After an unusually long time, your computer receives a DNS response message that the host name in your request message does not exist. This is a host you use every day.

a. List problems that may have happened and comment on their likelihood in broad terms like low. Give an explanation for your rating. (Draw the picture.)

b. Which is the most likely to have cause the long delay and failure to find your host’s IP address?

c. How would you test it?