Why have we not run out of ip addresses?

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With the massive growth in internet devices, shouldn’t we have used up all possible ipv4 numbers?

In: Technology

13 Answers

Anonymous 0 Comments

We have, essentially. There are five regional internet registries (RIRs) and in the last ten years they have all run out of new IPv4 addresses, most recently in November 2019 when the RIR for Europe, the Middle East, and Central Asia used up their last one.

Some individual ISPs still have unused addresses, and both ISPs and RIRs can recycle old addresses that are no longer being used.

Anonymous 0 Comments

1. We switched to ipv6 – this increased the number of ips from 2^32 to 2^128. A lot of infrastructure and network infrastructure switched immediately freeing up space for in ipv4 for other stuff.
2. We cheated. Routers became small devices to “lie” to the Internet and keep track of which device is making which connection while showing only one address to the web. Internal addresses start with 192.168 or 172.16.0.0-172.31. or 10. This is Network Address translation.
3. We Subnet more closely with CIDR and Variable length subnet masks to save addresses; we use network addresses as assignable in certain environments, Probably other cheating.

Anonymous 0 Comments

We ran out of unique IPv4 addresses a long time ago. The way it works is that your computer, smartphone, and other devices each have a unique address within your local network, provided by your network router. They all begin with the same numbers. So, all of your devices’ IP addresses might begin 10.20.30.xxx, where each device has a unique number (up to 255) in the fourth position.

That only enables them to “see” each other, though. In order to get out to the internet, you need a modem and an external IP address from your internet service provider. The modem passes the internet traffic to the router, which matches the unique IP address to the destination device’s local IP address. That way, you only really need 1 real IP address per local network.

Google “subnetting” if you’re interested in further research.

Anonymous 0 Comments

We did, sort of. We have way more devices than ipv4 addresses, but a lot of them are using the same address and hiding behind a local network. For most broadband setups, your entire WiFi network is only consuming one public IP and it’s using a whole bunch of local IPs behind your router.

This bought us some time. Ipv6 was invented to make sure this “never” happens again, it has a far (far far far) larger number of addresses.

Anonymous 0 Comments

Not every IP address is “unique”.

To the internet, all the devices in your house connected to your router is using 1 IP address provided by your internet company.

Anonymous 0 Comments

We have. We use tricks to put more than one computer on the same IP address. That’s why you have to set up port forwarding if you want to have a Minecraft server.

If your ISP does IPv6 and doesn’t rip you off, you can have an IPv6 address for every computer.

Anonymous 0 Comments

We did, sort of. We have way more devices than ipv4 addresses, but a lot of them are using the same address and hiding behind a local network. For most broadband setups, your entire WiFi network is only consuming one public IP and it’s using a whole bunch of local IPs behind your router.

Anonymous 0 Comments

There’s a thing called carrier grade NAT (Network Address Translation) that enables ISPs to transparently share single IP addresses across many clients.

It does this by mapping a set of ports for each client to the single IP address (like a switchboard, if you will), and the router (the brains of the network) knows which port belongs to who, and forwards the data on accordingly.

Alternatively, some places may be switching over to full IPV6, therefore freeing up IPv4 address space.

Additionally, the governing body of the Internet address space IANA (Internet Assigned Numbers Authority) is able to shift around the number blocks as needed between countries, including take them off you if you aren’t using them.

Anonymous 0 Comments

A technique called NAT helped out with that. It’s basically used everywhere both for business and in homes. Fiber connections aside, it’s also a contributing reason why we call the box at home ‘router’ and not ‘modem’ anymore (even though modem functionality may be built in for cable connections).

NAT works like telephone switchboard. Let’s say you call customer service at a major company, there could be 200 people answering the phone but there’s not 200 numbers listed under ‘Contact us’. There is one number that you call and then it’s split up internally. If they call you back, you typically only see their shared number, the one you called, displayed on your phone, not the individual number for the individual operator. Internally, if they need to call a colleague or manager they can use short numbers (“extensions”) like 0046 that doesn’t work outside their telephone system.

Connected devices work similar in a NAT:ed network. They get unique internal addresses and they can share “real” public IPv4 addresses for external connections. The router keeps track that device ABC asked for www.reddit.com, so all cat pictures from that connection should go back to that device. There are three ranges for internal use, with the vast majority of devices for private use is configured to use addresses looking like 192.168.0.x. So it’s likely that a number of people in any Reddit thread may actually have the same private IP address, but everyone in their own closed context “behind” their public address.

Anonymous 0 Comments

So there are two versions – at least two that are most common – of the Internet Protocol: IP version 4 (or IPv4), and IP version 6 (or IPv6).

IPv4 allows for 2^32 of unique addresses, or about 4 Billion-ish. This is the most common form of IP space in use today, and technically we have already run out. We’ve tried to expand the number of useful IPs by using something called NAT – or Network Address Translation. This uses what are call “private IP ranges” which create IP addresses that the internet as a whole can’t use, but people in an organization- like a business or school – can. If you’ve ever logged into your wifi router at home and notice the IP address starts with “10” or “192.168” then these are examples of private IP addresses. What NAT does is change that IP address to something the internet CAN use. For example, at home you might have a tv, laptop, and phone that have a different private IP, but when you browse the internet your ISP “translates” those private IPs into a single public IP. If you go to a website like whatsmyip on different devices, you’ll see the same address come up, and it won’t match the IP on your device. This is how, while we have “run out” of IPs, we can still all connect to the internet.

IPv6 was designed to combat this problem. IPv6 allows for 2^128 unique IPs, which is a number I honestly cannot even fathom. It’s not as common (yet) as IPv4, but I would expect that to change within the next decade. With IPv6, we can give every device – even smart or IoT devices – unique and public IP addresses. There are some security concerns with that, but those are being handled as the IPv6 rollout progresses.

Sorry for the long post…I took “explain like I’m 5” literally lol