DNS and IP Addresses

My topic, with Tim and Dana, for the  next Wiki page, is DNS servers and IP addresses.

I’d heard these acronyms before, and seen them around when I surf the internet or troubleshoot my router from time to time, but I never really knew what they were.

So here’s a basic rundown of the DNS:

The letters, DNS stand for ‘Domain Name System’. Domain Name Systems are a complex collective of smaller networks which helps to connect computers to internet webpages by translating the domain name that they desire to reach, into an IP address.

The computer connects to the DNS when the user types in an internet domain name, and the DNS relays the IP address back to the computer which then connects to the site which the IP address relates to.

If an IP address isn’t within a DNS server’s domain, it will send a message to the relevant domain and query them for the IP address and then send that information back to the relevant computer.

The DNS also identifies and locates computers by using IP addresses, so different computers that are connected to the internet all have separate IP addresses. These change frequently depending on the Internet Service Provider, or ISP. The IP address of a computer is determined by the router which might reset the IP address frequently or rarely depending on the user’s settings.

And here is a basic rundown of IP addresses (WARNING, they’re pretty complex even in basic rundown form):

An Internet Protocol address has two main purposes: to identify and locate the host device or network interface, and to identify webpages.

There are two main types of IP addresses, IPv4 and IPv6. IPv4 addresses are 32bit numbers, and are finite. So in 1995, IPv6 addresses were invented so that the internet can continue to grow.

IPv4 addresses have four octets, each divided by a decimal point. For example: 118.209.208.3, which is my current IP address.

There are 5 classes of IPv4 IP addresses, Class A, B, C, D and E. Each class is structured a different way and are allocated from largest networks (Class A) to experimental and rare networks (Class E).

IPv6 addresses are 128bit, and are 16 octets long. Each section of the IP address is separated by a colon ( : ) and they incorporate both letters and numbers. IPv6 addresses are also finite but provide enough IP addresses for the next 100 years at least.

Both IPv4 and IPv6 addresses are divided into two parts, the network identifier and the host identifier. Many hosts belong to a network and the size of the network determines what class it will be in and how many octets in the IP address are dedicated to the network.

The smaller the network, the more octets are dedicated to it and the fewer octets are devoted to the host. The larger the network the less octets are dedicated to the network and the more octets dedicated to the host. Class A IPv4 addresses are reserved for the largest networks, and so the network identifier is stated in only one octet, while the host is identified in the remaining three octets. It is a logical system because the larger the network, the more hosts it will need to identify. Whereas, with smaller networks, there are more of them and therefore there will need to be more space in order to find those networks.

The allocation of IP addresses is managed by the Internet Assigned Number Authority, or IANA. It allocates IP address blocks to ISPs and other entities.

Unicast IP addresses are the address for individual devices that are connected to the internet.

 

Here’s a pretty cool and simple explanation of the whole thing if mine was too complicated.