Networking Objectives Recap and understand the following network addressing terms IP address Domain name servers (DNS) Uniform resource locators How we find webpages!

A example IP address would be – 192.168.6.3 Networking IP address Every computer has a unique IP address. This allows computers to direct packets of data to the correct PC’s. IP address is split into 4 sets of numbers ranging from 0 to 255. A example IP address would be – 192.168.6.3 When we look for pages on the internet we very rarely enter their IP address.

http:// www. mysite .com /folder/ Index.html Networking URL A URL (uniform resource locator) is a web address! Why does it have a fancy name? Well the answer is that not everything on the internet is a web page! The world wide web is NOT the internet. As such URL allow us to find resources on the internet and NOT just finding web pages. http:// www. mysite .com /folder/ Index.html The above is an example of a typical URL.

http:// www. mysite .com /folder/ Index.html Networking Protocol http:// www. mysite .com /folder/ Index.html HTTP stands for “hyper text transfer protocol” and is the network protocol used to transfer web pages. Most web browsers will put this in for you!

http:// www. mysite .com /folder/ Index.html Networking DNS http:// www. mysite .com /folder/ Index.html This part is referred to as the domain name. It is made up of a series of domains read from right to left (bigger to smaller). This must be converted to an IP address.

http:// www. mysite .com /folder/ Index.html Networking Folder http:// www. mysite .com /folder/ Index.html A web server may have multiple folders. These work in the same way folders work on a standard PC.

Networking Webpage name http:// www. mysite .com /folder/ Index.html The name of the page you are looking for is at the end. Every website has a default page so if you do not specify a page then you will get the default. This is commonly known as the home page.

Networking Domain name www. mysite .com Domain names are a symbolic link to a IP address. Computers need to know the IP address of a web server in order to talk to it. Humans do not like having to remember loads of numbers so having your “.com” domain name is much easier to remember. Domains are read from right to left and are separated by full stops. “.com” or “.uk” are known as top level domains. This is why you can have a “amazon.com” and a “amazon.co.uk” which link to two different websites.

Networking Domains .com .uk .ca .fr Here are some top level domains. “.com” is the American commercial website domain. “.uk” is UK websites, “.fr” are French websites and “.ca” are Canadian websites.

Networking Sub domains .com .uk .ca .fr .gov .org .co .ac .biz .gov.uk – UK government websites .org.uk – UK organisations .co.uk – UK companies .ac.uk – UK academic institutions (university) .biz.uk – UK business websites

You will only have a few minutes to try. Networking Activity You can buy your own domain name! See if your name has been taken or not. Do a search for “domain name registration” and see which names are available. You will only have a few minutes to try.

The compulsory video explaining how DNS works! Click here Networking DNS lookup The compulsory video explaining how DNS works! Click here

Looking up the IP address in this way is known as a DNS lookup. Networking DNS lookup The top level domain server is contacted first (for example “.UK” or “.com”). This is a special computer which stores the IP address of all of the sub-domains. You can think of it a bit like a giant address book. This new “sub-domain” is contacted in order to find the IP address of the web server. This is then sent back to your browser which will then start to download your webpage. Looking up the IP address in this way is known as a DNS lookup. You can not download your webpage until you have the IP address. That means that if the DNS servers break down then you will not have access to the world wide web.

Make notes on – What is a DNS server? What is a URL? Networking Activity Make notes on – What is a DNS server? What is a URL? How does DNS work?