Except you can spoof an IP address or get another one from the ISP just by asking. You can spoof a MAC address too.
Intel introduced unique processor id’s back in the late 90s.
Comment on Phones have unique phone numbers, why dont computers have unique computer-numbers?
JakenVeina@lemm.ee 7 months ago
They do, it’s called an IP address.
Phones get numbers assigned to them by a cell service provider, in order to communicate on their network, which is basically the exact process for computers and IP addresses.
If you’re asking about the equivalent of like a SIM card, in the computer/internet world, that’s handled at higher layers, by digital certificates. And again, the process is almost exactly the same, except they don’t (usually) get put on physical chips.
800XL@lemmy.world 7 months ago
lemmyng@lemmy.ca 7 months ago
Phone numbers can be spoofed, and SIM cards can be cloned. The analogy stands.
jeffhykin@lemm.ee 7 months ago
Cell phones don’t get a new number every time they switch cell towers, so why do laptops.
Its not like I can write down the IP address of my friends laptop so I can send it a message once he gets to a new city.
lemmyng@lemmy.ca 7 months ago
Laptops don’t get a new IP address every time they switch from one AP to another in the same network either. Your cell phone will get a new IP address if it switches to a different cell network.
jeffhykin@lemm.ee 7 months ago
I can get VOIP calls behind a NAT without cell service. I’m asking how is that possible. Is the router somehow part of the same AP as cell service?
lemmyng@lemmy.ca 7 months ago
Whoa, that’s a sizeable edit to the post! Regardless the answer is pretty straightforward: your VOIP client (either the device if you have one or the software) is connected to a VOIP service which acts like a gateway for your client. Since the client initiated the connection to the gateway and is keeping it alive, you don’t need to make any network changes. Once the connection is established, standard SIP call flows (you can Google that for flow diagrams) are followed.
So no, you router is not part of the cell service. The VOIP provider is part of a phone service that receives calls and routes them for you, just like the cell towers are part of a telephony provider that routes calls through the appropriate tower.
SchmidtGenetics@lemmy.world 7 months ago
Its not like I can write down the IP address of my friends laptop so I can send it a message once he gets to a new city.
With static IPs that’s possible, but you already do that when you email them already.
JakenVeina@lemm.ee 7 months ago
Main difference there being that switching cities means probably switching ISPs. You can absolutely carry over your IP address when you move between the same provider, if that’s part of your service plan, and that may well happen with some ISPs even without it being part of your plan. There just isn’t really much of a need for people to carry a static IP, except for some businesses, and I’d say the main reason is that people don’t visit websites by memorizing and typing in an IP. They do memorize and type in phone numbers.
SchmidtGenetics@lemmy.world 7 months ago
[deleted]jeffhykin@lemm.ee 7 months ago
I can send a message to the IP address but AFAIK the message won’t get to him because he will alalmost certainly have a new address when he connects to the airport WiFi in the new city.
henfredemars@infosec.pub 7 months ago
IP address is really the best comparison here. Some computers share an IP just like entire call centers may share the same phone number. And neither IP addresses and packets nor phone numbers are properly authenticated without additional enforcement systems.
Internal networks exist for computers and phones. It’s a nice parallel.
JesterIzDead@lemm.ee 7 months ago
No, computers can’t share IPs
lemmyng@lemmy.ca 7 months ago
Sure they can. If you put a network behind a router they will share an egress/ingress IP. And there are certain high availability setups where computers share IPs in the same subnet for hot/standby failover.
JesterIzDead@lemm.ee 7 months ago
Yes, but no. The public IP is that of the router, which NATs packets to each host, each of which must have a unique private IP. The public IP does not reference or identity hosts behind the router. And that’s not how HA works. Only one host is assigned the active IP at one time.
IHateReddit@lemmy.world 7 months ago
They can share the same router and therefore have the same public IP.
JesterIzDead@lemm.ee 7 months ago
Yes, but no. The public IP is that of the router, which NATs packets to each host, each of which must have a unique private IP. The public IP does not reference or identity hosts behind the router.