IP address

[Ratna]

What exactly IP address is?

[sweetmaria]

http://en.wikipedia.org/wiki/IP_address


Anyone can use a simpler language to explain it OP?

[Tokek]

I'll use an analogy instead to try to explain it, though others can probably do a better job than me.

IP address is like your home address for your computer, it tells the world(or in this case the internet) where your computer is located and where to send data packets to. When you send a request for a web page (for example), your computer will include its IP address along with the request so the server where the web page is hosted will know who requested it and where to send the pages to. The actual process is of course more complex than this but this is the basic explanation, for more in-depth explanation, the wiki page linked by sweetmaria should do the trick.

[wombat]

IP stands for Internet Protocol. IP address is a series of numbers separated by dots allocated or assigned to every computer connected to the internet. It is a unique number to identify any given computer in a network. I shall not explain the subtleties of domain, firewall NAT etc.

[sergei]

Tokek's analogy is very good: IP address is a mailing address of the device. Every time you send a letter (request) to a friend (remote device), you put your message into an envelope (packet) with his postal address (destination IP) and your return address (source IP), so he can send you a reply (response).

IP address is a series of numbers separated by dots

That's a commonly used human readable form, a.k.a. dotted decimal notation. Inherently IPv4 address is a 32bit binary and could be represented in various notations:
binary: 11000000 10101000 00000000 00000001
octal: 300:250:0:1
decimal: 3232235521
dotted decimal: 192.168.0.1
hex: C0:A8:00:01

[Howie]

My guess, from the complexity of Ratna's question, is the best answer goes to Tokek.


....It's your computer's address.

[Ratna]

so IP address is MY computer's address? not the internet computer's address?
i have Facebook, every time i log in, my IP address say that i log in from Bogor, but i live in Jakarta.....why that happens?

[Pengad Nizk]

add IP ?

[Tokek]

so IP address is MY computer's address? not the internet computer's address?
i have Facebook, every time i log in, my IP address say that i log in from Bogor, but i live in Jakarta.....why that happens?

Your actual IP address is most likely a "private" IP address range, which means it's the designated address that are normally used inside private networks. Facebook probably grabbed the IP address of your ISP (Internet Service Provider, ie: Speedy, First Media, BizNet, etc), and their servers are located or registered in Bogor.

Let's imagine your internet provider (which I shall use the term ISP from now on) is like a gated housing complex and your house (computer) is inside the gated complex. Your ISP controls all the mail (data packets) coming and going to and from the complex itself, so all the mail from the outside world are first addressed to your ISP first (which is why it FB says you're logging in from Bogor) then the ISP will forward the mail to your address inside the complex. So when you go to facebook, your PC will send the request to your ISP with your IP address, then the ISP will put that request in an envelope with the ISP's address and forward it to facebook for you. Facebook then will receive it, process it and sends back the answer to your ISP, then your ISP will open the envelope, figure out your address and reforward it to your PC to display.

The reason they do this is because there are only so many IP addresses available before they have to repeat the numbers. So the ISP gets the unique IP address range to use for their network then they create their own "internal" or private IP address range for use within their network. This way the IP address can be used multiple times inside different ISP's or corporate networks throughout the world but still be "unique."

The set up is a bit like the postal service. You have millions upon millions of street names in the world, some are used in multiple locations, so your mailing address is usually formatted like this:

Name of recipient
Street Address
City, zip code
Province
Country

When you receive a letter, the main post office of your country will receive it first, then it will sort it and send it to the provincial post office, which then will resort it again and sends it to your city's post office which then will resend it to the nearest post office that serves your zip code which then will give it to your postal carrier to deliver to your house. The process is reversed when you send a letter out but still follows the same pattern.

The IP address set up is similar. You have huge blocks assigned to countries, then smaller blocks from that huge blocks assigned to the ISPs inside the country (provincial post office), then an even smaller blocks given to smaller ISPs that rents from the big ISP or their corporate clients (city post office), then those ISPs or corporate clients create their own "private" networks to spread to their customers/users (your neighborhood post office) and if you have a home network, you create your own little private network inside that as well.

I know my explanation is a wee bit confusing, but I hope that kind of gives you an idea or at least answer your question a bit. This is pretty much the very simplified version of it, the reality is WAY more complex and I'm not even sure I totally understand it myself.

[Ratna]

i still confuse, i change my Facebook password, and i log in again, but now i log in from depok not bogor, but i live in Jakarta and my interenet provider from Jakarta...what is happening here? if my IP address in bogor how come now from depok? how to make my IP address from Jakarta?