1. Summary DNS DNS Alexandra Tolbert Benefits How It Works Basics Katherine Barrios DNS Parts Phillip Nelson

2. 5 DNS is the foundation for name resolution in a TCP/IP network BASICS Used most by web browsers and email programs Locates servers Makes a user friendly name of a computer to it’s IP address DNS is commonly associated with the Internet

3. 5

4. Server names remain constant Easier to remember than numeric IP addresses 5 Convenience Consistency Simplicity

5. “.” com. edu.us. org. lsu.edu. google.com. gov.us. Domain Name Space

6. lsu.edu. moodle2.lsu.edu. business.lsu.edu. isds.lsu.edu. Domain Name Space computer1.business.lsu.edu. server1.business.lsu.edu.

7. “.” com. edu. us. org. lsu.edu. moodle2.lsu.edu.business.lsu.edu.isds.lsu.edu. lsu.edu. business.lsu.edu. webserver1.business.lsu.edu. Domain Name Space

8. webserver1.business.lsu.edu. Host Sub Domain Sub Domain 2 nd Level Domain Top Level Domain Root Domain Name Space

9. lsu.edu. moodle2.lsu.edu. business.lsu.edu. isds.lsu.edu. Zones

10. Name Server lsu.edu. moodle2.lsu.edu. business.lsu.edu. isds.lsu.edu. Name Server Primary Zone Database File Secondary Zone database file Name Server

11. Sends a query to a series of name servers to find the IP address of the requested computer Paths necessary to connect a client to its intended destination How name servers map user friendly names to numerical IP addresses Name Resolution Process

12. “Hey, I need directions to http://www.lsu.edu” Client

13. “ The domain name www.lsu.edu is not in my database or cache. I’ll try another DNS server.” Local Server

14. “I have authority to find that address! I will send a list of IP addresses for the edu. domain” Root Server

15. Root Server

16. “Great! I’ll ask edu. For the correct address.” Local Server

17. “Here is the IP address to the requested site.” Lsu.edu Server

18. “Thanks! I will forward this to the client and keep the address in my cache for awhile.” Local Server

19. “Thanks for the directions! Now to pay my fee bill on lsu.edu”

21. User Friendly Name (Host Name)IP Address Apple.com17.149.160.49 Koofers.com23.23.109.128 Microsoft.com192.168.2.1 Pintrest.com23.21.123.64 Twitter.com199.59.148.10 Walmart.com161.170.248.20