1. G053 – Lecture 09 Domain Names Mr C Johnston ICT Teacher www.computechedu.co.uk

2. Session Objectives Understand what the “Domain Name Service” (DNS) is, Understand the reasons for having domain names, Know how domain names are constructed, Be able to register a domain name and point the domain to a site.

3. TCP/IP - History In 1983 it was decided that all computers on the net should communicate using a standard protocol, A protocol is a set of rules – in English we must start sentences with a capital letter and end with a punctuation mark, Transport Control Protocol / Internet Protocol (TCP/IP) was chosen, It is made up of 5 layers: The top level provides the protocols which your applications use e.g. email, http, and ftp The middle layers breaks data up into packets and adds destination and source addresses. They also reassemble at the other end The bottom layer sends / receives data

4. TCP/IP - What It Means Each computer (both servers and clients) connected to the internet need an address so they can send and receive data, Internet Protocol states how this address is constructed: A 32 bit binary number spilt into four parts of 8 bits by a full stop, The parts of the IP address are then decimalised for ease of use. For example: 10110010.00101000.00000011.01011000 is 178.40.3.88 Each computer that is connected to the internet needs a unique registered IP Address, Your computer is assigned an IP address automatically by your ISP when you connect to the internet.

5. Accessing Web Pages To access a webpage you need to enter the IP address for the server where the pages live into web browsing software IP address for Google's server IP address for Google's server entered into browser and page appears Is this really the best way to access content on the internet??

6. Domain Names - Overview The “Domain Name” was invented to make the web more accessible, Access webpage's using IP addresses would intimidate some people and most would struggle to remember them, Domain names are a textual way of accessing websites – instead of entering an IP address companies can register their name or a related word and link it to their IP address, You can register a domain name for as little as 99p for 2 years. The “Domain Name Service” (DNS) links your IP address and domain name so that either become an address for your site, Basically DNS is big database listing domain names and their linked IP address. Your ISP contain DNS listings on its servers.

7. Theoretical Example DNS Domain NameIP www.google.co.uk209.85.229.104 www.bbc.co.uk212.58.246.90 uk.msn.com213.199.164.110 www.virginmedia.com212.250.162.12 www.facebook.com69.63.181.12 In theory a DNS table would look something like this – in practice however they are a lot more complicated! ntchosting.com. 394 IN A 216.65.1.250

8. Domain Names - Example “Domain Names” have three different parts www.computech.me.uk/quiz This part is the domain name This part is the extension or suffix This part is the directory where the web page lives

9. Choice #1 – Domain Name The first choice is what your domain name should be??? The obvious choice is your business name….. What if its taken or not possible e.g. B&Q??? Something key to do with your business – DIY!!!

10. Choice #2 - Extension There are various different domain name extensions which your domain can have, Typical domain names include:.com – international company.org – none profit organisation.net - network services such as ISPs.co.uk – UK company.gov – government.ac.uk – UK college / university You can investigate the available extensions for your domain by visiting an Accredited Registrar, You can only reserve domain names which don’t belong to anyone else - some will not be available due to restrictions.

11. The fee varies depending on extensions and also supplier – its good to shop around, Registrations last for 2 years before they need to be renewed, NOMINET.uk are an organisation who handle domain registrations in the UK and issue domain name certificates once applications are processed by the registrars.

12. Free Domain Names Some companies offer free domain names, http://www.freedomain.co.nr/ http://www.co.cc/ http://www.dot.tk They will then forward traffic to your account on the web server, Some place adverts as compensation for the service,

13. Registering Names To register a domain name you should use an Accredited Registrar, You can only register domains which are not taken by somebody else, Registration fees are set by the Registrars and do vary from one to another – its good to shop around.

14. Topic Exercise Visit the links for the further reading and read them. They will help you complete this topics exercise. Write a short report explaining: What a domain name is and the advantages they have, Options for a suitable domain name for your website along with a decision and justification, A screen shot showing the different extensions available, and their price, Justify which domain extension you are choosing rather than others – you could opt for a free one or make a purchase. Register a the domain name for your project using - its worth registering an email account first. Write a short explanation of how you registered your own domain name - include screen shots as evidence. The forward URL will be www.computechedu.co.uk/yourName e.g. selinaP www.computechedu.co.uk/yourName

15. Further Reading http://www.webopedia.com/TERM/D/domain_name.html http://www.internic.net/faqs/domain-names.html http://www.nwfusion.com/news/2004/0323icann.html http://www.igoldrush.com/alt_ext.htm http://www.domain-names-registration-uk.com/domain-extensions.htm http://www.nic.uk - controls UK domain registrations and lets you lookup who owns a domain and when it expires. http://www.nic.uk http://www.cheapdomains.uk.com - example of domain name registrar http://www.cheapdomains.uk.com http://www.123-reg.co.uk – example of domain name registrar http://www.123-reg.co.uk http://www.freedomain.co.nr/, http://www.co.cc/, http://www.dot.tk - free domain registrations http://www.freedomain.co.nr/http://www.co.cc/http://www.dot.tk