IP Addresses Explained

On the internet, every server is given a unique number, or what is called an IP (Internet Protocol) address. This number can be regarded as a ‘telephone number’ which will allow other computers to find and gain access to files regardless of where they are. The IP address is equivalent to 4 bytes (32 bits), and each byte is known as an octet and can have a value of between 0 and 255, so IP addresses are written in the form of numbers, such as 123.456.78.9.

IP addresses of 32 bits allow in theory more than 4 billion unique addresses, but in actual fact, the real number is much less. Certain varieties are set aside for special purposes so the number of available IP addresses is restricted. Web sites can however get around this limitation by using shared hosting or virtual servers. Instead of using one server for one web site, shared hosting can enable several sites (sometimes hundreds) to be hosted on the same server. Each of these sites will have the same IP address, and they will be uniquely identified by their domain name (e.g. mydomain.com).

With the introduction of version 6, there are plans to expand the number of IP addresses (We currently use version 4) of the Internet Protocol. IPv6 has IP addresses which are 128 bits wide. This will give you an almost unlimited number of unique addresses, but will also take several years to carry out because of the very costly process of upgrading the Internet infrastructure.

Shared hosting explains the problem of limited IP addresses for web sites, but there is also a requirement for IP addresses for each personal computer which connects to the Internet in order to browse the web or to send emails. Rather than allocate each PC a unique IP address, Internet Providers is able to use a system of ‘dynamic addresses’. This implies that each time you connect to the Internet through a dial-up or DSL modem you will be assigned a different IP address.

We have previously discussed how to use a web hosting company in order to host a web site, but there are no reasons why you cannot host a site on your home computer. For most people, though, the biggest technical difficulty is that they connect to the Internet using an IP address which is dynamic. Dynamic addresses make it more difficult to host a web site from your home. As the IP address is constantly changing, nobody would be able to find your site unless you somehow inform them of your current IP address. There are many dynamic DNS services, nevertheless, which will allow you to assign a domain name to a site with a dynamic IP address. Every time you are given a new address your computer will automatically notify the service, which will in turn update its DNS (Domain Name Server).

Hosting your web site on your computer at home, however, might not be a good idea. The computer will need to operate server software and will need a high speed Internet connection. Your home Internet connection might probably be a lot slower than those used by hosting companies, so it is possible that your web pages load more slowly – especially if they have many graphics. If you have a smaller personal site with little visitors, however, it may be possible to host your own site. You can obtain dynamic DNS as either a free or a subscribed service.


Martin Redford is contributing editor at WebDesignArticles.net. This article may be reproduced provided that its complete content, links and author byline are kept intact and unchanged. No additional links permitted. Hyperlinks and/or URLs must remain both human clickable and search engine spiderable.

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