DNS

• Learning Outcomes
• Resources
• Lab
• Assignment

Learning Outcomes

• describe the role of the following in the DNS: registry, registrar, and registrant
• explain the role of root name servers, top level domain servers, and authoritative name server
• explain the process of recursive DNS resolution
• register a second level domain
• configure resource records (RR) of the following types for an application: SOA, A, CNAME, MX, NS, TXT, AAAA
• retrieve DNS information using dig

Resources

• Pro DNS and BIND 10 I recommend that you read chapters 1 and 2 and the sections on the DNS protocol and DNS queries from chapter 3.
• How a DNS Server works. (video)
• slides

Lab

None.

Assignment

1. In a text file answer the following questions:
   1. What is the phone number of the technical contact for apple.com?
   2. What are the name server records for ubc.ca?
   3. What are the mail exchanger records for sfu.ca?
   4. What kind of record is langara.zoom.us?
2. If you have not already done so, resize your lab1 VM down to a “f1-micro” instance type and update the “A” DNS record for myapp.4949NN.xyz if needed so that the application works by its domain name.
3. In your local development environment or Google Cloud Shell, create a new ExpressJS applicaiton, mysecondapp.
4. Start the application listening on port 8081.
5. Use web preview to test the application.
6. Implement the /webhook route for this application exactly the same way as for myapp. You can copy the code and the deploy.sh script.
7. Create a new GitLap project mysecondapp and follow the instructions to do the initial stage, commit, and push.
8. Create new firewall that allows traffic in on port 8081.
9. Deploy mysecondapp to your lab1 VM by hand on port 8081.
10. Create a new “CNAME” record for mysecondapp.4949NN.xyz that points to myapp.4949NN.xyz.