Is there any number goes with our computer to internet ?
Um, yes, it's called your IP address. You answered your own question!
how many ip is there in my computer
why it is 4 digits?
Can we change it edit?
It's not 4 digits.
Hiding your IP address is a fairly simple matter. This is commonly done via a virtual private networks [VPN], but, other approaches exist, nearly all of which rely on use of a proxy server to interface with external websites. All of this is well known to hackers seeking anonymity to engage in nefarious activites.
There are many other ways web sites can to track you. Cookies for example.
To some extent yes, cookies can reveal what sites are visited, what pages were looked at, but not much more than that.
They can't determine where the computer is physically located or identify who is using it.
There was a time when processor serial numbers could retrieved by some versions of Windows to check for duplicate installs over the internet. I don't know if this is done anymore. Just changing certain components on a system could trigger a reactivation request, but that was internal, not sent over the internet.
EDIT: it did just occur to me that if you put a small EPROM on the CPU chip, you could program identically fabricated chips to have different serial numbers but I don't think this was ever done.
It was the Pentium III, wiki article:
I had forgotten how old this was.
As for hard drives, although the drives do have a serial number, I was able to replace all 4 drives on my system by cloning them, and Windows didn't ask for an activation, although Windows 7 ended up "renumbering" the drives, which fortunately didn't affect the boot process. My system is multi-boot, and XP and XP X64 didn't renumber the drives, only Win 7. This causes some confusion if doing an image restore with Win 7, since the drive letters are scrambled. The BIOS drive numbers were not changed, so the boot up process into any of the operating systems was not affected.
When I do a format / restore on a backed up partition (I have a file / folder backup utility), I have to restore the volume serial number after the format to keep Windows from asking for activation.
I'll be damned. Didn't know about that or if I did I forgot it. I guess they DID use an on-chip EPROM. Thanks for the info.
Again I had it wrong. I was sure the hard drive serial numbers were drive-specific.
Hard drives do have drive specific serial numbers, but Windows doesn't appear to check them. However I've had strange things trigger a reactivation, such as updating a video driver, so it's not clear what or how much of a change triggers reactivation.
CGI programs can collect more information than that and can save it in cookies. I suspect they often keep track of the username so that the communication can be continued with the same username at a later time.
Each computer connected to the Internet is given an IP address which traditionally is a quartet of numbers with values 0 - 255 and separated by a full stop. Some Internet providers allocate the number to your computer dynamically and some use a fixed address. In either case it is difficult to change this number without losing access. As someone else has pointed out it is possible to hide this address from other sites by using proxies and VPNs etc.
In a typical home environment, the Internet provider will allocate the IP address for your home router. Your home router will, in turn, allocate an IP address for your home computer(s) and other home internet devices to use. The allocated IP addresses will often be allocated from the private 192.168.0.x range. (See https://tools.ietf.org/html/rfc1918 for details on the 192.168.x range)
The router does address translation (NAT) so that the IP address that is visible to servers on the public Internet is not the same as the IP address that is used on your computer.
The IP address on your computer can be seen by going to a DOS command prompt and typing "ipconfig". For instance, my private IP address is:
Windows IP Configuration
IPv4 Address. . . . . . . . . . . : 192.168.1.121
Subnet Mask . . . . . . . . . . . : 255.255.255.0
Default Gateway . . . . . . . . . : 192.168.1.1
The translated IP address that was allocated by your provider and is seen from the public Internet can be most easily determined by visiting a web site such as http://www.whatismyip.com.
In the case where IP is dynamically allocated, most home connections, it's actually very easy to change it.
Generally all you need to do is switch off your router for a minute or two and the IP you had been using will go back to the pool of adresses owned by your provider.
When you power up again you'll be be assigned an IP from the pool which is very unlikely to be the same one you previously had.
Static IP's are generally assigned for use by servers and can't be easily changed since the IP is directly associated with the server's web address www . something
Follow up questions please.
What about your cell phone connection, is the IP for that dynamic or fixed? If dynamic, when does it change?
If I connect to the net on a public wifi, is my IP that of the router or unique to my device?
I cannot speak for cell phones. There are a number of plausible implementation strategies.
With a public wifi, your IP address belongs to you. The wireless access point to which you associate works essentially as a piece of wire [It operates at layer 2]. The "router" which acts as your default gateway may or may not be on the same piece of hardware. It is virtually certain that you will be assigned a private RFC1918 IP address while you are connected to the wifi network. Address translation will be used so that the source IP address that appears when you browse the public Internet will reflect the connection from the wifi provider to the Internet rather than the connection from you to the wifi provider.
If you are on an extended WiFi network, you will likely be able to retain your IP address as you move from one access point to the next. If you move from one wireless provider (e.g. from Hilton Honors public wifi to San Antonio airport public wifi) then you will pick up a new IP address from the new wireless provider.
The point of RFC1918 private IP allocation taken together with Network Address Translation is to allow network providers (such as public wifi hotspots) to assign the same private IP addresses time after time without conflicting with any server IPs on the public Internet. The only requirement is that the same private IP address is not allocated twice on the same layer 2 network.
Using an Android phone, is there any way to look at your current IP address?
Separate names with a comma.