1. DNS Domain Name System

2. Lots of people use the internet for different reasons. DNS Plays a big role in the internet. The DNS translates domain names into IP addresses. Domain Name System

3. The Size of the DNS How would you describe the size of the Domain Name System? Fig. 2 Image Source - http://www.businessfacilities.com/blog/uploaded_images/eick1_lg- 740752.png Fig. 2

4. The 3 main components of the DNS are: Domain Name Space The Domain Name Space - This is a database of name related information. Domain names can be both uppercase and lowercase, and are defined by RFC 1034 to not be case sensitive. This means that www.myexample.com is exactly the same as WWW.MYEXAMPLE.COM. www.myexample.com Top Level Domain 2 nd Level Domain

5. The 3 main components of the DNS are: DNS Name Server DNS Name Servers – The second major component of the DNS is the Name server. Every zone has a main name server which is the source of the resource records. This server can be updated by an administrator; there is a secondary backup server which has copies of the main servers data. DNS name servers also have the ability to perform zone transfers; this is where the name server searches the database for the entered web address to find the IP address for that webpage. If for some mysterious reason the domain name is not on the main server, the DNS name server transfers the website it’s looking for to the second server, and so on to different zones until the correct IP address is found.

6. The 3 main components of the DNS are: DNS Resolvers DNS Resolvers - Access to the Domain name database is through a resolver which could either be a program or part of a computer operating system. The resolver will send requests to the name servers to return information requested by the user. If the domain name is in the user’s closest zone, the main name server has the ability to deal with the request. If the main server can’t locate the domain name, it asks one of the root servers. The root server then responds with a list of name servers that have the information. This process is repeated until the local name server receives the IP address for the domain name. The local server then saves the record, and then returns the DNS data to the original requestor.

7. How do these 3 components relate to each other? These 3 components relate to each other because they use one another for the DNS Service to be active. The user who wants to access a website enters the domain name into the domain name space; The DNS Name Space is used by the other 2 components to access the domain names. If the local DNS name server can’t find the domain name, then the DNS Resolver comes into play and uses root servers to locate the domain name and sends the IP address back to the local zone server. Overall, all 3 main components of the DNS work together in order to fulfil the user’s request.

8. The function of the DNS The internet as we know it today plays a major role in some people’s lives, for example: some businesses can’t function without the internet. As stated before, the DNS is the backbone of the internet, without it, there wouldn’t be an internet. The function of the DNS is to translate domain names into IP addresses because the internet only understands IP addresses, not domain names. When users attempt to access another computer on the network, a structure must be in place to map the domain names to their equivalent addresses.

9. Is the operation of the Domain Name System affected by any legislation in the UK? The operation of the domain name system is affected by a couple of legislations within the UK, an example is domains have to be different from one another, meaning two domains cannot be the same, however domain names can be different even in the slightest such as one domain could be: www.myexample.com, and another could be www.myexamp1e.com. (Charlotte Waelde, Date unknown) “No two domain names can be identical. There can only be one "harrods.com". The word "Harrods" could however be registered under one of the country domains. Thus along with "harrods.com", "harrods.co.uk" can also be used as a domain name. In addition, variations on the name "harrods.com" can be registered, for example "harr0ds.com" or harrods1.com. The permutations are limited only by the imagination.”

10. What is the most significant limitation to the continued operation of the Domain Name System? There are many active domain names and a limited amount of IP addresses to assign to these domain names in the Internet protocol version 4 (IPV4). The last domain to be registered on IPV4 was taken in February 2011 As there are too many domain names and not enough IP addresses to assign to future domain names. Internet Protocol version 6 (IPV6) was created. It is another Internet protocol which was released after the Internet Protocol Version 4 (IPV4) ran out of addresses. Every host requires an IP address in order to communicate with one another. The vast growth of the internet has demanded more IP addresses than it was physically possible with IPV4 to handle.

11. Conclusion Overall, as I said earlier, the DNS plays a huge role in the internet and most of our lives. Without it there wouldn’t be a WWW, which means you wouldn’t be watching this presentation today.

12. References. 2012.. [ONLINE] Available at: http://www.businessfacilities.com/blog/uploaded_images/eick1_lg-740752.png. [Accessed 10 January 2012]. http://www.businessfacilities.com/blog/uploaded_images/eick1_lg-740752.png How the DNS works - YouTube. 2012. How the DNS works - YouTube. [ONLINE] Available at: http://www.youtube.com/watch?v=2ZUxoi7YNgs. [Accessed 10 January 2012]. Animation Movie by Centr.http://www.youtube.com/watch?v=2ZUxoi7YNgs Charlotte Waelde, Domain names and Trademarks: What is in a name? [Online]. Available at http://www.law.ed.ac.uk/it&law/ch4_main.htm

13. How the DNS Works How the DNS works - YouTube. 2012. How the DNS works - YouTube. [ONLINE] Available at: http://www.youtube.com/watch?v=2ZUxoi7YNgs. [Accessed 10 January 2012]. Animation Movie by Centr. http://www.youtube.com/watch?v=2ZUxoi7YNgs