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Levi's PC Consulting
Your IP Address is:
First off no, I did not have to "probe" your computer, break through your firewall or hack you to find your external internet IP address.

You gave me your IP when you requested this page. Read on to find out more about this IP address thing.
When you request a web page, either by typing in an address or clicking a link you make a request to a server. This request needs to contain a few key pieces of information so the server can send the web page to you. One of these key pieces is your IP address.

What is an IP Address?

IP stands for Internet Protocol, the protocol (a set of rules) requires that all of the devices on the internet have a unique IP address to communicate with each other over the network.

An IP address is similar to a phone number, if you want to make a phone call you need a phone number to make the call from.

On the internet everything uses IP addresses instead of phone numbers.

You ask for something on the internet, probably a web page and so long as your request contains amongst other things a valid IP address the web server answers the phone call, accepts your request, hangs up the phone, digs around and finds the page you asked for, brushes the dust off it then calls you back at the IP address you provided earlier and sends you the web page.

This all happens very quickly and is a bit more involved than that but it's a basic way of thinking about it.

Where did your external IP address come from?

Your internet service provider or ISP assigns it to you when you login or connect to the network.

Chances are your IP address will change from time to time. Most ISPs assign you an IP address from an IP pool, which means you pretty much get a random IP from your ISPs pool or range of IP addresses when your modem connects or comes on-line.

This is an IP lease which like most leases implies that you only have it for a certain amount of time before you have to return it for another one or renew your lease on the current one. Lease times vary from one ISP to another, anything from a few hours to weeks at a time.

For the average internet user this is perfectly fine, you ask for something on the internet and it gets sent to you.

Like a phone number you say?

To bring this back to a phone number, in effect your phone number would change all the time but because your are only making outbound calls (requests for web pages) you don't need to know your phone number, no one calls you unless they are returning a request from you and that all happens on it's own in the background.

Your system hands off your current IP every time you request a web page (just like it did above) and the server uses it to send the reply back. If in ten minutes from now your IP address changes the next time you make a request the web server will send the response to that number instead.

What does this IP address look like?

A typical 32bit IPv4 address looks like this
There are four octets or four sets of numbers separated a "." with each containing a value between 1 and 254.
This creates an address space of 4,294,967,296 unique addresses.
While four and a quarter billion addresses seems like a lot it's not enough for current demands, as it turns out we ran out of IPv4 addresses in back in 2011.

Due to the very limited and ever diminishing availability of IPv4 addresses there is a transition to 128bit IPv6 addresses under way which increases the address space to
340 000 000 000 000 000 000 000 000 000 000 000 000 unique addresses.
I had to get a 64bit calculator to derive that IPv6 number the 32bit calculator included with Windows 7 (64bit) errored out after 10^31.99999999999999999999999999999.
This is to be expected you can only count so high with 32bits. This speaks to limitations of 32bit systems and our need to transition to systems that can handle larger numbers, anyway I digress back to IP addresses.
A typical IPv6 addresses looks like this:
As you can see IPv6 significantly increases the available address space over IPv4, which we need but for now IPv4 is still pretty much the norm.
Check back every once in a while and see how often your IP changes.
On a side note IP address ranges are assigned to specific countries and locations, you can fairly easily determine some ones geographic location by IP alone. This is a commonly used method for preventing or denying users from other countries.

I should also mention that while a DHCP or PPPoE IP may seem "random" to you, your ISP knows exactly what IP has been assigned to your account.
Your IP address one of the small bits of the data you share every time you surf the Internet and request a page. IP addresses are probably logged on 99% of the websites you visit for one reason or another most often security or statistics.

Should you be worried? No, probably not so long as what you are doing is legit and you are not making people angry, there are very few reasons to be concerned. You've been surfing the Internet for how long prior to reading this?

Just be aware the Internet is not this huge anonymous place any more, you (the account holder) are responsible for the data that travels to and from your IP address. Something to keep in-mind before giving your neighbour Carl your WiFi password.
For a deeper look into IP addresses, you can check out the Wikipedia page here.
© Levi's PC Consulting 2016