Shared IP vs. Dedicated IP

Dedicated IP Address

An IP address is assigned to every web server and other electronic device connected to the Internet, like computers, routers, and switches. It is composed of four numbers whose digits are 0–255 and which are separated by periods or dots. An example is, which is often used for routers. A web server’s IP address is usually static, fixed, or dedicated, meaning that the server is always identified by the same address.

Shared IP Address

Most websites, on the other hand, are hosted with shared IP addresses on a shared hosting web server. This means that many people’s websites each have their own partition on the server, and the owners share the cost of maintaining the server, making this option cheaper than a dedicated IP address.

Shared IP addresses were not always available. Early on, every domain name was assigned a separate IP address. The rapid growth of domains and the finite number of available IP address led to the sharing of IP addresses. But since servers are able to match the domain a user enters into a browser with a domain that shares an IP address with myriad others, it’s not a problem.

Who Needs a Dedicated IP Address?

There are three particular benefits to having a dedicated IP address that may make you decide to spring for this more expensive option.

For Private SSL Certificates

First, if you wish to use your own Private Secure Sockets Layer (SSL) Certificate, you need to have a dedicated IP address. SSL Certificates are a protocol with an encryption system for keeping a message transmission on the Internet secure. They are used for https web sites used in electronic commerce, for transmissions dealing with health care, and for accepting credit cards online.

Shared SSL certificates are available through web hosts, and if you choose this avenue, you do not need to have a Private SSL Certificate, and can still use a shared IP address. Another alternative is to use a payment service like PayPal.

For Anonymous FTP

Some web hosts require a dedicated IP address to enable anonymous FTP (file transfer protocol), the standard for transferring files between two computers connected to the Internet. Anonymous FTP enables a computer to allow anyone using the FTP software to access a directory of files on its disk drive that has been set aside for this purpose. The service is referred to as Anonymous FTP, because the user signs in using the username “Anonymous.” Enabling anonymous FTP requires a dedicated IP address. You are advised to check with your web host if this is of interest to you.

For Your Own Servesr

If you want to set up your own domain name server, rather than use a web host’s server to translate IP addresses into domain names and vice versa, you will need a dedicated IP address as well. If you want complete control over your website and all decisions related to it, the same thing applies.

Blocking of Shared IP Users

In order to block spam activity, certain organizations have taken to blocking an IP address rather than specific users. This has happened in both directions with Comcast: all users from Comcast have been blocked by some sites, and Comcast has itself blocked all users from particular sites itself (this is a separate issue from the BitTorrent blocking issue that has been in the news). If an IP’s address is blocked, then all users sharing that address are blocked. This means that many innocent users are on the receiving end of a ban, and may not even realize that, for example, their e-mail is not arriving or that they are not receiving e-mail intended for them.

This is enough to make some people want to have control over their own mail server. And this, again, indicates a need for a dedicated IP address.