S kills : none Concepts : domain , domain name, host, IP address, domain registrar - PowerPoint PPT Presentation

slide1 n.
Download
Skip this Video
Loading SlideShow in 5 Seconds..
S kills : none Concepts : domain , domain name, host, IP address, domain registrar PowerPoint Presentation
Download Presentation
S kills : none Concepts : domain , domain name, host, IP address, domain registrar

play fullscreen
1 / 18
S kills : none Concepts : domain , domain name, host, IP address, domain registrar
122 Views
Download Presentation
rumor
Download Presentation

S kills : none Concepts : domain , domain name, host, IP address, domain registrar

- - - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript

  1. The domain name system Skills: none Concepts: domain, domain name, host, IP address, domain registrar This work is licensed under a Creative Commons Attribution-Noncommercial-Share Alike 3.0 License.

  2. Where does this topic fit? • Internet concepts • Applications • Technology (communication) • Implications • Internet skills • Application development • Content creation • User skills

  3. Internet hosts 155.135.55.165 www.csudh.edu

  4. IP addresses and domain names 65.55.12.249  = www.microsoft.com 65.55.12.249 www.microsoft.com

  5. Domain name servers do the conversion www.microsoft.com 65.55.12.249 DNS server 65.55.12.249 www.microsoft.com DNS server

  6. www.microsoft.com 65.55.12.249 DNS server 65.55.12.249 www.microsoft.com DNS server http://www.zoneedit.com/lookup.html

  7. The parts of a domain name • The particular host is called som • The organization that owns the name it is csudh • This host is at an educational organization som.csudh.edu

  8. How are these hosts related? • bpastudio.csudh.edu • www.ucla.edu • sws.csudh.edu • chemistry.stanford.edu

  9. How are these hosts related? • som.csudh.edu • www.csudh.edu • sws.csudh.edu • chemistry.csudh.edu

  10. A unique host som.csudh.edu

  11. Some generic top-level domains • .edu, educational • .com, commercial • .gov, government • .org, non profit • .net, networking organizations

  12. Some country code top level domains • .us, United States • .mx, Mexico • .cl, Chile • .uk, United Kingdom • .tv, Tuvalu

  13. Some TLDs use a four-level hierarchy • http://www.google.co.uk/ • http://www.unam.edu.mx/ • http://www.ox.ac.uk/ • http://www.google.com.mx/

  14. The system is hierarchical

  15. Name servers are decentralized ? Root name server ? Edu name server CSUDH name server

  16. Summary We’ve seen that domains are groups of related computers. Domains have names. Individual hosts have unique, fully qualified domain names. The top level domains seldom change, but people are constantly registering new second-level domains. Domain name servers keep track of the correspondence between IP addresses and the corresponding domain names. Responsibility for maintain ing the lists of names and addresses is decentralized.

  17. Self-study questions Are there more hosts in the .edu domain or the csudh.edu domain? Can two hosts have the same domain name? Can two hosts be in the same top level domain? Can two hosts be in the same second level domain? Is the <your name>.com domain name available for purchase? If so, how much would it cost? Why do you get an error message when you try to go to http://www.google.xom? http://wwww.google.com also returns an error message. Why?

  18. Resources • A DNS lookup web site (forward and backward): • http://www.zoneedit.com/lookup.html • For most generic TLDs there are many registrars and a competitive registration market place: • http://www.icann.org/en/registrars/accredited-list.html • The registrar for .edu is a professional society called Educause: • http://net.educause.edu/edudomain/ • List of organizations responsible for registrars in the country code domains: • http://www.iana.org/domains/root/db/#