Is there any number that goes with our computer to internet?

[anorlunda]

This is very interesting stuff, and quite hard to understand what is happening, and why. I think it is remarkable that the whole thing works as smoothly as it does.

Using @Vanadium 50 's tip, I looked up the IP for my phone. It showed two IPs, one V6 address registered to my provider, and also a V4 address.

I rebooted the phone, it gave me new V6 and V4 addresses.

I looked at the IP on my iPad connected to a home wifi operating on Comcast cable. It showed 10.0.0.0 as the IP. Then, I started the wifi hotspot on my phone and connected to iPad to that. Now the iPad shows no IP at all, yet it still works and a page request from the iPad gets a response returned to the iPad.

I know that I could add another link to the chain (after jailbreak and using the Foxfi app) by making the iPad a bluetooth hotpot, while the iPad is getting wifi from my phone. Similarly, I could tether a second phone to the first via USB, then make that second phone a wifi hotspot. I have no practical reasons for doing so, I just find it curious that these things work at all, and that no matter how many links in the chain the identity of my device will still be traceable.

 

[imort]

Hello,
Is there any number goes with our computer to internet ?

Hey
You always have your own IP address (4 digits are looking like 128.128.128.128, each of them can be from 0 to 254 with some restrictions).
So your IP address can be tracked up to your home router device.

Usually, you'll have one external IP address for the all yours network devices at home, where your home internal IP addresses can look like 192.168.x.x or something like that. It names the private network addresses (192.168.x.x, 10.x.x.x, 172.16.0.0 - 172.31.0.0)

 

[nikkkom]

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.

It's not EEPROM, it's fuses. It has many uses. For example, to permanently set allowed CPU frequency range after CPU was tested ("binned") by manufacturer and this particular chip's tolerances are determined. For disabling parts of chip which were found to be defective (cores, part of the cache, on-die GPU, etc).

https://www.reddit.com/r/hardware/comments/3onp1m/how_do_companies_like_intel_or_amd_disable_cores/

"Fusing use to be done by way of focusing a laser on regions of metal in the die to intentionally overheat the metal in a catastrophic failure manner causing the circuit to then become an electrical open. This method of "fusing off" certain areas of the chip has been replaced with actual electrical fuses in the sense of the phrase in which certain parts of the chip (the fuse) is over-volted in such a way that the flow of current combined with Joule heating (ohms law) overheats the metal line in the fuse causing it to melt in a catastrophic manner resulting in an electrically open circuit.

Fusing is done for most of your typical "chip harvesting" yield enhancement techniques. Sram redundancy, core segmentation, etc."

 

[rbelli1]

Laser fusing was done on external bridges on some AMD processors. You could reprogram the fusing with an Xacto and a conductive pen.

BoB

 

[rcgldr]

Regarding ip addresses, cable modems support up to 16 external ips. DSL static block ip modems start off with 8 ips, but use 3 of them for the ISP, leaving the user with 5 external ips. There are DSL modems that provide a larger static block (more than 5 user ips). ISP's may limit this, for example my cable ISP limits the number of external ips to 3 (at cost of $7 (USA) / month for the 2nd and 3rd ip). Usually, the modems use the MAC addresses of the devices connected to the modem, along with some database at the ISP to assign external ips to the devices. With some ISPs, the user can configure part of the ip if it's available. With this setup, the network between the modem and the devices is an extension of the internet, not a local area network, and the only local area network would be on the internal side of a router connected to the modem.