IP Addresses Explained
This is a very basic description and I have over simplified the processes to make it easier to understand. An IP (Internet Protocol) Address is number assigned to your computer, either temporarily or permanently by your Internet Service Provider (ISP). Every computer on the Internet has a unique IP Address assigned to it. A permanent (non-changing) IP Address is called a "Static IP". Where as a temporary IP Address is called a "Dynamic IP". An IP Address is very much like your home phone number. When someone dials your phone number your home phone rings because that specific telephone number is tied to your home phone and no one else's. That is similar to how an IP Address works. The main difference is most of the time we don't enter the numerical IP Address, we type in a name like (easyipfinder.com) to get to a computer or server on the Internet. The domain name you type into your browser is translated into an IP address, behind the scenes, by way of a Domain Name Server (DNS). We have all seen telephone numbers translated into words maybe something like 1-800-buycars, because that is easier to remember than a ten digit number. In the same way, www.google.com is easier to remember than 126.96.36.199 (which is really the IP address for their site, go ahead try typing it into your browser).
You may ask why have two types of addresses? Well it is simple, the two main reasons are cost and bandwidth (capacity of the internet servers and connections). Static Addresses require dedicated connections, these are expensive to maintain. Dynamic Addresses are designed as cost saving and bandwidth saving measures for ISP's. This is accomplished by allowing multiple users to share a connection (or a Static IP Address). Your Dynamic Address is actually tied to Static IP Address and works like a "temporary" Static IP Address. Just like with any phone system, there are only so many connections that can be made at one time. Have you ever tried to make a phone call and got an "all circuits are busy" recording? That means the phone system has reached its full capacity. It doesn't happen very often, because the phone company and your Internet Service Provider (ISP) both use a system which makes the valid assumption that not everyone will be using their phone or computer at the same time. In order to take advantage of this, the main connections of your phone system and the internet are shared.
Here's an Example: About 12 years ago, when everyone had dial-up internet connections, I worked for a local ISP. Some of you may remember how the old dial-up system worked. All the ISP's customers called the same phone number, which was tied to a large bank of modems. Since you could only have one modem per phone line, if the first line was busy it would roll to the next available line until you ran out of available modem lines. Phone lines and modems weren't very cheap back then and customers wouldn't stay with you long if they got a busy signal every time they tried to connect to your Internet Service. So the company came up with a ratio that they used to determine how many phone line/modem connections they needed based on the number users they had signed up for Internet Service. If I remember correctly, it was only about 1 to 5 or 20%. So if you have 100 users you need only 20 phone lines with modems connected to them. They were assuming that they would only have 20% of their users trying to connect to the internet any one time. This worked surprisingly well and saved the ISP a ton of money.
For a Static IP Address to be useful, it requires that you have a direct full time connection to the internet. But more importantly, a Static IP Address gives the internet a consistent direct connection to you! Because they are expensive, Static IP Addresses are usually reserved for web servers and ISP connections to the internet backbone. Most web servers use a Static IP Address so that every time you type www.google.com the DNS knows to covert that name into the IP Address 188.8.131.52 and viola you are connected to Google every time. If you have a Dynamic IP Address you are "sharing" that address with other users and you are being assigned (or leased) an IP Address for each session that you are connected. If you disconnect and reconnect with a Dynamic Address you will most likely receive a different IP Address. If you want to host a website or login to a computer remotely, this could be a problem because you need to know that computer's Dynamic IP Address. If your Dynamic Address changes, you would lose your connection to your computer or website and it would be almost impossible to find out what the new IP Address is from the Internet side.
If you have a hi-speed internet connection at home, you probably have a Dynamic IP Address and your computer remains connected the internet the entire time it is turned on. Though you have a Dynamic IP Address, it may not change for days or even weeks as long as you do not power down your computer or modem. If you login in remotely to your home or office computer on a regular basis, you probably already know that a power failure or a Dynamic Address change could happen at anytime. If you are away from home when this happens, you may have no way of checking to find out what your new Dynamic IP Address is. Until Now! You can use our free software to check for any changes in your IP Address. Download Remote EasyIPfinder 0.1
Modems, Routers and Internal IP Addresses
Above we have be talking about External IP Addresses. These are IP Addresses that are visible to the Internet. There are also Internal IP Addresses. These addresses are only visible to other local (meaning in your home or office) computers or equipment. IP Addresses actually have ranges of addresses that are set aside for specific uses. Any IP Address that starts with "192" (ie.192.xxx.xxx.xxx) is an Internal Address. If you have a high speed Internet Connection your modem may or may not have a DHCP (Dynamic Host Configuration Protocol) Server built into it. If it does it will convert your External IP into an Internal IP Address. This process is called Network Address Translation or NAT. NAT is a great security feature because it acts as a firewall protecting your computer from unwanted Internet traffic. Routers also use DHCP and NAT to split and share your Internet connection. They do this by assigning Internal IP Addresses to all the local computers.