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.
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.
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.
NAT sort of accidentally includes what is called a “stateful firewall”. It blocks inbound connections because it doesn’t know where they should go. IPv6 eliminates the need for NAT but doesn’t prevent stateful firewalls. It is just as easy to implement stateful firewalls (actually a bit easier) for IPv6 without NAT. The difference is that the choice is yours, rather than being a technical limitation.
For example if I had a smart microwave I would want to ensure that there is some sort of firewall (or more likely for me not connect it to the internet at all, but I digress). However I may want my gaming computer to be directly accessible so that my friends can connect to my game without going through some third-party relay, or maybe my voice chat can be direct between me and my friends for extra privacy and better latency.
Also relying on network-level protection like this is a good idea in general. Eventually a friend is going to come over with an infected network and connect to your WiFi. With just NAT this will allow the malware on their computer to access your microwave as they are “inside the NAT”. If you were applying a proper stateful firewall you would likely apply it to all traffic, not just internet traffic.