IP questions

[Gomar]

Is every computer connected to the Internet itself considered a node, and has a unique IP?

What if I buy a new PC, and give away my old one to my 13 year old nephew? Does that mean the IP goes to his house? Then he moves to say Kentucky, IP remains same eventhough I live in NYC?

So does my new PC have the same IP, or a new one?
Is my old PC (now in another state) assigned a new IP as 2 nodes cant have the same IP?

If ISP assigns new IP every time you log on, then how can the FBI track anyone? Does the ISP keep a database of every IP for every user ever logged on?

[RicheemxX]

No you've got things a bit confused. Internet IP addresses are ISP dependent not computer or user specific. Every internet device has a mac address that is unique but not a unique IP. Your ISP assigns you a specific unique IP address from the list of addresses they have which can be "leased" for a specific period of time. Once that lease is up it might be renewed or you might get another one. But for the most part your Internet IP address is never doing to be unique to you as an individual or any single device for an extended period.

Your internet IP addresses is unique to you, your computer or your network at the time you have it but its not really yours.

IP address - Wikipedia, the free encyclopedia

If ISP assigns new IP every time you log on, then how can the FBI track anyone? Does the ISP keep a database of every IP for every user ever logged on?

Short answer is yes. Just like the telephone company keeps a log of every call you make your ISP logs which customers it assigns an IP address to.

edit: Added more info.

[RicheemxX]

Here's a little more detailed explanation that might help clear things up.

Individual home users have what is called a Dynamic IP address that is temporary and is going to be assigned typically to their modem each time it accesses the Internet. They are "leased" or borrowed from a pool of IP addresses that have been given to their ISP to be shared among all their customers.

Major corporations, businesses, people with internet servers ect use Static IP addresses which are never changed. They serve as their permanent Internet address which makes it easier and more reliable for remote computers to connect to them. Some ISPs offer this to customers but its usually reserved for business use.

Your home address is only temporarily going to be assigned to you. Back in the day with dial-up you got a new IP from the ISP every time you dialed in. Now days with broadband you keep your IP a little longer. Lease times vary, and they may actually never change it. It just depends on their settings.

[Nude_Lewd_Man]

Also, note that there is a difference between your LAN (internal network) IP and your WAN (external network) IP addy...

Generally, and unless modified by someone, most home networks (LANs) will be using the 192.168.0.x/24 or 192.168.1.x/24 but your IP for your network will be something completely different.


To check your LAN IP:

Start --> Run --> "cmd" [Enter] --> "ipconfig" (or, in *nix, "ifconfig") [Enter]

Look for 'IPv4 Address'.


To check your WAN IP:

What Is My IP Address - Shows Your IP Address

Read the IP in the middle of the top of the page.



Unless you have requested and/or configured otherwise, you will be using DHCP and not have a static IP.

[Nude_Lewd_Man]

Others have explained your doubt clearly,I like say some additional information.
There are two IP address:
1)Public ip address(Static and Dynamic)
2)Private or Local Ip address
Public IP address:
It is the one provided to you by your ISP.This is the address which will be visible in the internet.It can be found by visiting sites like IP-Details.com .
Private IP address:
Private IP addresses are typically used on local area networks like School,College,etc.,It can be found by Start->Run->Cmd->type "ipconfig" and enter.

Public IP address can be further divided as Static and Dynamic IP address.
Dynamic Ip address:
When ever you restart the modem/router if the public IP changes every time or over a period of time then your IP is Dynamic Ip address.
If the public ip address doesn't change when restarted then it is Static Ip address.

The ISP will keep record of which Public IP address is assigned to which Customer(Machine ip address) at what time.
It is not a public record.But,With a warrant the records are provided to Police or FBI or any government agency.

Just a couple of points, but it isn't just a public IP that that section I've changed to RED text relates to.....it's ANY address that that would affect......

Also, to add that it is also possible to have a public address within your private addressed network, though that is not the norm...