2. Objectives  Basic Introduction to DNS  Purpose of Domain Naming  DNS Features: Global Distribution  Fully Qualified Domain Name  DNS Lookup Types

3. Introduction to DNS (Domain Name System)  Provides resolution of names to IP addresses and resolution of IP addresses to names  Domain Name Service/Domain Name System 74.53.142.83 www.islington.edu.np

4. Purpose of Domain Naming  Addresses are used to locate objects  Names are easier to remember than numbers  You would like to get to the address or other objects using a name  DNS provides a mapping from names to resources of several types

5. DNS Features: Global Distribution  Data is maintained locally, but retrievable globally No single computer has all DNS data  DNS lookups can be performed by any device  Remote DNS data is locally cachable to improve performance

6. Fully Qualified Domain Name (FQDN)  Identifies a host’s name within the DNS namespace hierarchy  Host name plus DNS domain name = FQDN Host name DNS domain name

7. DNS Lookup Types Lookup Types Forward LookupRequests name-to-address resolution Reverse LookupRequests address-to-name resolution

8. IP address for islington.edu.np? IP address = 74.53.142.83 DNS Server DNS Zone Types: Forward and Reverse Lookup Reverse Lookup DNS Server Name for 74.53.142.83? Name = islington.edu.np Forward Lookup

9. Conclusion

10. Thank You