Seriously, my knowledge ends with:
- It offers a shitload of IP addresses
- They look really complicated
- Something about every device in your local network being visible from everywhere?
- Some claim it obsoletes NAT?
I get that it’s probably too complicated a subject for an ELI5, so if there are good videos or resources explaining it in less than half an hour, feel free to share.
IPv6 has several changes to the specification, but since this is ELI5:
When you were a child, your friends would call your house and a parent would answer the phone. They’d ask to talk to you, and your parents would hand the phone off to you. That might have been because you were too young to have a phone, but IPv4 with NAT works the same way because there are so many “houses” and only enough phone numbers for the houses, not all the people that live in them.
For IPv6 it’s like your friends can call you directly on your cell phone. And they can call your brothers and sisters, your cat, your dog, your TV, your refrigerator, and the backyard squirrels. There are so many phone numbers that everyone can have their own.
How do I handle whether I want my phone number to be known to the world?
Does my phone number ever change on its own or can I freely change it?
Who has the phone book?
Feel free to turn this into an ELI5years in general IT after a career change where I started from scratch.I didn’t know about that part, doesn’t that make it necessary for everyone to have a firewall? What’s stopping someone from port scaning my Chinese smart microwave and attack it?
This is getting out of ELI5 territory, but the way it works with IPv4 is when something on the internet needs to access your devices, it sends a request to your IP address (your house) along with a port number. Your router (that runs your firewall) decides if it should forward the request to the device inside your network. By default, it usually says “no” unless you tell it otherwise.
With IPv6, you’d still have a router, most likely, but it would be “watching” all of the IP addresses for your devices, not just a single one for your entire home.
This does add a fair bit of complexity, but my guess is that if we ever do start getting blocks of IPv6 addresses as home users, most routers will probably come with default firewall blocking rules pre-configured.
I’m already on a connection where I don’t get an ipv4 address, just a block of ipv6 addresses.
My ISP-supplied router comes with a firewall that I can’t configure or disable.Really? Just out of curiosity, what kind of connection are you on? I have two ISPs, one of which provides a single IPv4 address only, and the other provides one IPv4 and one IPv6 address.
It’s a coaxial cable connection from Vodafone in Germany, using Dual Stack Lite.
It uses IPv6-only links between the provider and the customer, but does not use NAT64 translation. When a device in the customer network sends an IPv4 packet to an external destination, the IPv4 packet is encapsulated in an IPv6 packet for transport into the provider network. At the LSN, the packet is decapsulated and NAT44 is performed
Based on this reply, I get the distinct impression that you know a LOT more about networking than your original ELI5 post lets on, and almost certainly more about the subject than I. I work in tech, but not with networking specifically; most of my knowledge is from way too many years and dollars spent on homelabbing.
One of my internet connections is a DSL connection; by default, they provide a single IPv4 address. My DSL modem has an option to enable IPv6 tunneling through IPv4, but I was never able to get it to work, and customer support was completely clueless. I suspect this isn’t something their network supports and they’re just counting on their users not caring. My other connection is over satellite (Starlink), and as far as I am aware, they’re only providing a single IPv6 connection, not a block of addresses.
To make things easy, I’ve just blocked IPv6 at my firewall, and I use policy-based routing on my PFsense box to send traffic to either connection depending on latency/bandwidth requirements (Streaming goes to satellite, VoIP goes to DSL, etc). I know that IPv6 has improvements beyond just “more addresses,” but at this point I can’t really justify enabling it on my network. It would only be used internally, and I just don’t see any tangible benefit.
I’m on FiOS and I just had to turn on IPv6 on my router (it’s disabled by default on older Quantum Gateways). It works and they are assigning /56 blocks, I think it’s DHCPv6 but I haven’t looked in a while.
You can set up your own IPv6 server, and it will be accessible from every other IPv6 device. Do you want to create a Lemmy server using only your phone and Verizon mobile data? Yes you can! *
* Instructions for installing Linux environment on Android phone and setting up free DNS and HTTPS certificates are not included.
That’s the main point. IPv4 fails because half of all existing IPv4 devices cannot access the other half of IPv4 devices directly, they have to go around using some kind of relay server, which inevitably complicates communications and costs extra money.
It’s just a larger address space, nothing particularly special. Just more numbers
If you use IPv6, you don’t need to have concepts like rfc1918 / "private ip spaces, so if every ip is unique, they can be used publicly you don’t need NAT
I’m guessing you don’t need DHCP anymore either?
What’s the difference between an ipv6 address and a MAC address then?MAC addresses are link-local device identifiers, used by the switches and routers and WiFi access points that talk directly to the devices in question. Switches and routers maintain a table of which MAC to send a packet to based on the IP address - I.e. which actual port to send the data frames down.
There is DHCP for IPv6, but the IPv6 stack is supposed to be able to detect which subnet it’s router is in and then just pick addresses on its own (it does look for conflicts before committing to an address). This is called SLACC (stateless address auto configuration).
NAT is unnecessary because there are so many addresses, as others have mentioned; but I did want to point out that NAT is not used for security. Just because it obscures your devices does not make them any safer. All IPS routers have a firewall to one degree or another (could be as simple as “no incoming connections”; which is bad and lazy but it happens). Firewalling - examining incoming traffic against a set of rules for allowing or denying - is the correct way to secure any network, IPv4 or IPv6.
I guess the thing I mostly don’t get is:
If it’s just an extension of the address space, then why is it still such a big deal?
Why didn’t they add some sort of ipv4 compatibility layer into the new protocol and flip the switch everywhere 15 years ago?It took me 15 seconds with chatgpt
IPv6 is the newest version of the Internet Protocol (IP), which is used to identify and communicate with devices on the internet, like phones, computers, and smart home gadgets.
ELI5 Explanation:
Imagine the internet is like a huge city with billions of houses (devices). To send mail (data) between houses, each house needs a unique address. The older version, IPv4, only had about 4 billion unique addresses, and we’ve run out of them because the internet has grown so big.
IPv6 is like a new system of house numbers that has way more possible addresses — so many that we could give an address to every grain of sand on Earth and still have extras. This makes it easier for every device to have its own address without sharing or using tricks like NAT (which hides multiple devices behind one address).
Why It Looks Complicated: IPv6 addresses use longer strings with both letters and numbers (e.g., 2001:0db8:85a3:0000:0000:8a2e:0370:7334), so they seem more complex than the simpler IPv4 addresses (e.g., 192.168.1.1).
Why NAT Might Not Be Needed: With so many unique addresses available, IPv6 allows each device to connect directly to the internet without needing NAT, which was a workaround for sharing a single IP address among many devices.
Would you like me to find a video or visual resource for a quick overview of IPv6?
Yes
Here are some beginner-friendly videos that explain IPv6 clearly and concisely:
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IPv6 Explained Simply – This video provides an easy-to-understand overview of the basics of IPv6, covering why it was created and how it functions. You can watch it here.
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IPv6 Basics for Beginners – This tutorial delves into how IPv6 addressing works, its structure, and the comparison between IPv4 and IPv6. Check it out here.
It took me 15 seconds with chatgpt
Good for you. I prefer interacting with humans. Your ChatGPT text gives me the info I’ve read 10x before, but have trouble parsing into something I can grasp.
It doesn’t touch the real world implications for day-to-day admin work, pitfalls, what not using NAT actually means, if dynamic IP addresses are still a thing, maybe share a funny anecdote…It’s completely sterile.
And I have no idea what type of algorithm decided why these are the recommended videos.
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