The question above for the most part, been reading up on it. Also want to it for learning purposes.
There aren’t many benefits from using IPv6 on LAN, as far as I can tell, unless you need more addresses than are available in the private address ranges.
And that point you’re not in a home, you’re in a data center lmao
I mean, if you have around 17 million containers running services, maybe.
@BaldProphet
What’s the smallest container around? How much RAM would that take?edit: FROM scratch let’s you run bare binaries on Docker.
Would be very interesting to see how far that could get. What sort of payload/task would be interesting for all those containers?
@Sandbag @bdonvrDoesn’t need to be a “traditional” container. Modulo noisy-neighbour issues, wasm sandboxing could potentially offer an order of magnitude better density (depending on what you’re running; this might be more suited to specific tasks than providing a substrate for a general-purpose conpute service).
@gedhrel
wasm sandboxes can take IPs? Regardless, if we’re just talking density, I can put multiple IPs on a single interface or create a ton of virtual interfaces. That’s boring, though.Yes. The sandbox gets whatever capabilities you expose to it.
It’s definitely an interesting hypothetical. Some homelabs that I’ve seen run crazy enterprise gear and are certainly capable of running thousands of very small containers, while others are running repurposed consumer equipment or SBCs like Raspberry Pis with less computing power and RAM.
Of course, in a self-hosted or homelab environment, there would be little utility to running that many network or web services. It would be a neat experiment, though. Seems like the kind of thing that Linus Tech Tips would attempt.
I tried converting my internal and external self hosted setup to IPv6 only, like it’s the trend nowadays. But halfway through it I couldn’t really see the point
(Whoops, accidentally hit “Delete” instead of “Edit” and Lemmy doesn’t ask for confirmation!! Boo!! I’ll try to retype my comment as best I can remember)
I’ll buck the trend here and say “Yes, for a home LAN, it’s absolutely worth it. In fact for a home LAN it is more important than in a data centre. It is absolutely the bees’ knees for home and is worth doing.”
All of that depends on how your ISP does things. When I did it, I got a /56, which is sensible and I think fairly common. If your ISP gives you anything smaller than a /64, (a) your ISP is run by doofuses, but (b) it’s going to be a pain and might not be worth it. (I now live in literally one of the worst countries in the world for IPv6 adoption, so I can’t do it any more)
The big benefit to it is that you can have your servers (if you want them to be) publicly reachable with one unique address, the way the Internet was originally designed to work. This means you can use exactly the same address to reach them outside the network as you would inside the network. Just make one AAAA for them and you can get to it from anywhere in the world (except my country).
When I did it, I actually just set up 2 /64s, so a /63 would have been sufficient (but a /56 is nice). Maybe you can think of more creative ways of setting up your networks. Network configuration is a lot of fun (I think).
I had 1 /64 for statically-assigned publicly-reachable servers. Then I had a separate /64 for SLAAC (dynamic) end-user devices, which were not publicly reachable (firewalled to act essentially like a NAT). (Sidenote: if you do go to IPv6 for your home network, look into RFC7217 for privacy reasons. I think it’s probably turned on by default for Windows, Android, iOS, etc., these days, but it’s worth double-checking)
Not having to deal with split horizon dns or nat hairpinning is pretty nice, especially with so many things using DoH with public resolvers nowadays, like android or firefox.
I just put A and AAAA in public dns so things work either ipv4 or ipv6 on the outside. On the inside everything works on and prefers ipv6 so it just works on the inside too. Nothing ever even attempts to use the wrong (public) A record on the inside.
Sigh… not an ISP, but the service I rent my server from only provides me with a /128. Yes that’s right, exactly one IPV6 address and not one more.
Oof, that’s a very obvious sign they do not understand how IPv6 is supposed to work. At all.
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My ISP dynamically allocates a /64. I don’t even know why they do that.
@duncesplayed
You can always tunnel if your ISP won’t play nice: https://tunnelbroker.net/
@SandbagMy ISP delegated me only one /64.
That’s less fun. I believe you’ve either got to put everything on one SLAAC network (no static IPs), or you’ve got to use DHCPv6 (with a smaller network size) instead of SLAAC.
Right, everything is on SLAAC. My ISP only delegates /48 ~ /56 to business customers (according to their customer service).
Thankfully, RFC 7217 made SLAAC-only networks sufferable - you don’t to expose your MAC address to the entire world for stable addressing.
No, I like living in my nat cocoon so I don’t have to worry as much about all the devices on my network. Jk it’s turned on, but I don’t usually enable it on devices
Get a firewall. Malicious STUN, ALG DoS attacks, just these things make your NAT router less secure than you think it is.
Thank you!!
If you don’t want your devices to be accessible from the internet, you want a firewall. Treating NAT like a firewall is a bad idea.
But still, if I understand correctly, with NAT you can just use one firewall for your router and with IPv6 you’d need a firewall for each of your devices. This seems like a lot more to manage, right? But maybe I still don’t understand the concept of IPv6.
Edit: Apparently I don’t understand the concept of IPv6.
That’s not correct, but it shouldn’t preclude you from applying defence in depth.
Firewall and NAT are separate concepts. You can still have a firewall on your router when using IPv6. I don’t know how many consumer-grade routers handle it well though.
IPv6 is the future so I’d say yes. Dual stack is the way to go. If you can get public address block from your ISP thats great. If not I’d recommend HE tunnel or something similar. Just remember to firewall as ever device is reachable in most configurations.
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I’ll buck the trend and say “yes, for a home LAN, it is the bees’ knees”. I don’t do it now because my country (and hence my ISP) does not do IPv6, but for most places it’s worth doing.
It depends on how your ISP does it. When I did it before, my ISP gave me a /56, which is pretty sensible and I think fairly common. If you get smaller than a /64, (a) your ISP is run by doofuses, but (b) it’s going to be a pain and maybe not worth it.
A /56 was much bigger than I needed. I actually only used 2 /64s, so a /63 would have been fine, but network configuration is fun (I think), so maybe you can get creative and think about different ways of allocating your network.
I had 1 /64 for statically-assigned, publicly reachable servers. And then I had a separate /64 for SLAAC (dynamic) allocated personal devices (laptops, phones, etc.) which were not publicly-reachable (firewalled essentially to act like a NAT). (Sidenote, if you are going to use IPv6, I recommend turning on RFC7217 on your devices for privacy reasons. I think these days it’s probably turned on by default for Windows, Android, iOS, etc., but it’s worth double-checking)
The big benefit to using IPv6 is that all of your home machines can be (if you want them to be) reachable inside your network or outside your network using exactly the same IP address, which means you can just give them a fixed AAAA and access them from anywhere in the world you like. If you’re into that sort of thing, of course. It’s a lot of fun.
Thank you! I just want to say, I’ve also been curious about ipv6 every now and again for a long time, and this thread has helped me to understand more.
Because devices in your LAN will all be accessible from the internet with IPv6, you need to firewall every device.
It becomes more of a problem for IoT devices which you can’t really control. If you can, disable ipv6 for those.
Wait, ipv6 doesn’t require port forwarding to expose something to the internet?
Port forwarding is exclusively a NAT phenomenon.
In IPv6 every device should in theory have a public address - just like how every computer had a public IPv4 address back in the 1980s ~ 1990s.
However, most sensible routers will have a firewall setup by default that blocks all incoming connections for security reasons. You still need to add firewall rules.
This is correct. My router however doesn’t have that level of firewall. It’s either all allowed or nothing is.
There’s no “should in theory”. It’s only a possibility due to sheer number of possible combinations. No one was ever going to make every device public. It makes absolutely no sense. Why would your company’s printer be online or isolated networks or VPNs? There’s no point.
IP addressing is just a way to give a globally unique number to each device. It’s just a number.
And there wasn’t a real public/private distinction when the Internet was still in its infancy. Printers were indeed given “public” addresses because people needed a number for it.
If you don’t want your printer to be reachable by the public Internet, use a firewall to block outside connections. If you can use NAT, you certainly can use a firewall. Heck, they are almost the same thing if you have been using the Linux kernel (iptables/nftables handle firewalling and masquerading with the same tool!)
Routability is not the same as reachability. With NAT transversal you can reach my “private” hosts all the same, although you can’t route to me because I don’t have a public address.
It’s not necessary to firewall every device. Just like how your router can handle NAT, it should be able to handle stateful firewall too.
Mine blocks all incoming connections by default. I can add (IP, port range) entries to the whitelist if I need to host a service, it’s not really different to NAT port forwarding rules.
The argument for IPv6 that there could be a unique address for 200 devices for every person living on the planet was much more compelling when network security was a more simple space.
Nothing has changed about why that is compelling: NAT sucks and creates nothing but problems.
Network security is almost the same with IPv6.
If you rely on NAT as a security measure you are just very bad at networking.
I mean that, when IPv6 started filtering out to non-specialists, network security wasn’t nearly as complex, and nor was the frequency of escalation what it is today. Back when IPv6 was new(ish), there weren’t widespread botnets exploiting newly discovered vulnerabilities every week. The idea of maintaining a personal network of internet-accessible devices was reasonable. Now maintaining the security of a dozen different devices with different OSes is a full time job.
Firewalling off subnets and limitting the access to apps through a secured gateway of reverse proxies is bot bad networking. That’s all a NAT is, and reducing your attack surface is good strategy.
So even though the device has a public address, the route is through the firewall, hence the ability to filter traffic?
Right. Packets still have to go through your router, assuming that your router has firewall turned on, it goes like this:
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Your router receives a packet.
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It checks whether the packet is “expected” (a “related” packet) - by using connection tracking.
For example, if ComputerA had sent something to ServerX before, and now the packet received by router says “from ServerX to ComputerA”, then the packet is let through - surely, this packet is just a reply to ComputerA’s previous requests.
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If step 2 fails - we know this is a new incoming packet. Possibly it comes from an attacker, which we don’t want. And so the router checks whether there is a rule that allows such a packet to go through (the assumption is that since you are explicitly allowing it, you know how to secure yourself.)
If I have setup a firewall rule that says “allow packets if their destination is ComputerB, TCP port 25565”, and the received packet matches this description, the router lets it through.
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Finally, the packets that the router accepts from the previous steps are forwarded to the relevant LAN hosts.
I understand this part :) I use a fairly complex firewall at work though I only know bits and pieces from reading different manuals. I think the part I didn’t understand was how exactly the routing worked differently in IPv4 vs v6. I get that because NAT happens in IPv4, packets can’t be routed at all without the firewall/router but I wasn’t sure what was the mechanism by which v6 made sure that packets went through the router, especially when you have stuff like v6 DHCP relays.
Ah, I misunderstood your original comment, oops! But yes, IPv6 packets are routed just like IPv4 ones, just without the NAT’ing process i.e. the packet remains untouched the entire trip.
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Yes, the firewall is still your transition point from your internal network to your ISP network. Just like with ipv4, you should be configuring your ipv6 firewall to only allow designated traffic into your network from the internet.
Haha, no not really. IPv6 has the ability to provide public IP address for each device, but that doesn’t mean it will have to. Other than number of possible addresses, nothing is different. Routing, firewalls, NATs, etc. All remains the same.
IPv6 doesn’t support NAT… Or am I woefully out of date.
But your home router will just firewall like it does already but you don’t have NAT as a simple fall back for “security”. It does make running internal services much easier as you no long need to port forward. So you can run two webservers on port 80 and they be bother allowed inbound without doing horrible load balance or NAT translation.
IPv6 has NPTv6, which allows you to translate from one prefix into another.
Useful if you’ve got dual WAN, and can’t advertise your own addressing via the ISP. You can use NPTv6 to translate between your local prefix and the public prefixes. But NPTv6 is completely stateless. It’s literally a 1:1 mapping between the prefixes.
IPv6 has both NAT66 and NPTv6. (Note that NPTv6 was once called NAT66 too, but I am referring to the “stateful, one-to-many” NAT66 here. Yeah, it’s confusing.) NAT66 is more like the traditional stateful NAT that all of us know and understand.
The router does have a firewall but it blocks everything inbound by default. Some routers (at least mine) do not offer the granularity to filter traffic for certain devices (no NAT either). It’s either allow all in or nothing.
When you enable IPv6 and switch off the firewall (since you can’t host anything otherwise), every device becomes exposed to the internet.
Then unless the devices have a firewall themselves, all is exposed. Not just the web services, ssh and the rest as well.
There was a way around it however but not something everyone will be able to do with their home router. I had to ssh to the router using ISP admin credentials leaked on the internet, then create a file in init.d that loads a custom iptables file with the firewall rules I needed for IPv6. NAT for IPv6 however was not supported by the kennel used for my router.
Ipv6 doesn’t need NAT
Definitely dual stack if you do. The real benefit of IPv6 is that, supposedly, each of your internal devices can have its own address and be directly accessible, but I don’t think anyone actually wants all of their internal network exposed to the internet. My ISP provides IPv6, but only a single /128 address, so everything still goes through NAT.
Setting it up was definitely a learning process - SLAAC vs DHCP; isc’s dhcpd uses all different keywords for 6 vs 4, you have to run 6 and 4 in separate processes. It’s definitely doable, but I think the main benefit is the knowledge you gain.
And the biggest disadvantage of IPv6 is that each of your internal devices has its own address and can be directly accessible from outside. So you need to completely rethink how you do security.
Isn’t that what tburkhol addressed in their first paragraph? Or are you suggesting further steps than just putting those devices behind NAT? I am not at all trying to be snarky, I actually want to know more about this.
You don’t need to use nat on ipv6. Most routers are based on Linux and there you have conntrack.
With that you can configure by default outgoing only connections just like nat and poke holes in the firewall for the ports you want specifically.
Also windows and I think Linux use ipv6 privacy extensions by default. That means that while you can assign a fixed address and run services, it will assign random ip addresses within your (usually) /64 allocation for outgoing connections. So people can’t identify you and try to connect back to your ip with a port scanner etc.
All the benefits of nat with none of the drawbacks.
And can be identified/tracked individually by outside entities. In IPv4, a website sees both my device and my kid’s device as the same IP. In IPv6 they’re different so this just provides more ways for them to track you.
That’s the reason for rcf 4941. It randomises the host part of your IPv6 address.
First of all they use much more than the device IP to identify individual devices. IPv4 is no longer all that useful for identification with things like CGNAT being common.
But with IPv6 they’ll see my device IP, then they’ll see the same device with completely different IP, then again. Same for my kid’s device. But again, all of the above applies. It is a concern, but there are much better ways of tracking you anyways.
Your ISP is doing it wrong, which I guess you already know. I get a /64 net via DHCPv6 for my LAN which is pretty standard.
+1 to dual stack. Too much of the internet is v4 only, missing AAAA, or various other issues. I’ve also had weird issues where a Google/Nest speaker device would fail 50% of the time and other streaming devices act slow/funky. Now I know that means the V6 net is busted and usually I have to manually release/renew. Happens once every few months, but not in a predictable interval.
Security is different, but not worse IMO. It’s just a firewall and router instead of a NAT being added in. A misconfigured firewall or enabling UPnP is still a bad idea with potentially worse consequences.
Privacy OTOH is worse. It used to be that each device included a hardware MAC as part of a statelessly generated address. They fixed that on most devices. Still, each device in your house may end up with a long lived (at least as long as your WAN lease time) unique IP that is exposed to whatever sites you visit. So instead of a unique IP per household with IPv4 and NAT, it’s per network device. Tracking sites can differentiate multiple devices in the house across sites.
This has me thinking I need to investigate more on how often my device IPv6 (or WAN lease subnet) addresses change.
I get a fat /48 network, just in case I need one septillion, two hundred and eight sextillion, nine hundred and twenty-five quintillion, eight hundred and nineteen quadrillion, six hundred and fourteen trillion, six hundred and twenty-nine billion, one hundred and seventy-four million, seven hundred and six thousand and one hundred and seventy-six individual IPs.
IPV6 is pretty wild, we could effectively give every service connecting to every client, in every direction, for every single individual bit its own dedicated address without getting anywhere near using that address space.
Just wait until IoT takes off and every key on your keyboard has a unique address
The server I have with ovh has ipv6 setup, but only 1 of my VMS on it has an address. It’s a lot harder to get your head around then it looks, no NAT. Firewall everything
Depends on how you define “worth it”. Most selfhosting is done not for worth, but for a hobby.
Hobbies are often worthwhile. Maybe not financially, but often psychologically.
Some times not financially or psychologically, and they also make my wife mad when I fat finger some config.
There’s a pretty interesting series on the topic at Tall Paul Tech’s YouTube channel (here’s the most recent: https://youtu.be/WFso88w2SiM). He goes into quite a bit of detail over the course of a few videos about how he handled everything and highlights some of the trials and tribulations with the isp. It’s not a guide per se, but definitely stuff worth thinking through.
Here is an alternative Piped link(s): https://piped.video/WFso88w2SiM
Piped is a privacy-respecting open-source alternative frontend to YouTube.
I’m open-source, check me out at GitHub.
For LAN, no. If you have a router NAT’ting traffic and providing DHCP service there’s really no need for ipv6. Almost every ipv6 enabled service provides both 6 and 4 usually and NAT figures it out, and many still provide only 4, meaning you can’t just get rid of ipv4 entirely.
If your ISP has modernized and is actually providing an ipv6 address, I suppose there’s probably a tiny benefit of being able to go ipv6>ipv6 when routing, bust most all devices nowadays can handle NAT translation from ipv4 to ipv6 and vice versa with no routing penalty. I don’t know if there are any ISP’s out there who can provide static ipv6 addresses without a NAT router to your entire LAN though.
If you’re buying a vps or something ipv6 is easier to get a static address for.
That of course leaves the last good reason: why not? If you’re doing homelab hosting stuff why not experiment with ipv6 and fully modernize your network. They suck to type in but it’s fun to know your stuff is brand new and using the “best”.
I have currently an issue with a WebRTC SFU not working behind a IPv6 to IPv4 translation, at least I suspect that is the cause.
It’s good to learn, because it will become more common as time moves on, particularly if you get into the datacenter/cloud/ISP industry. It’s less important for the general home user, but it is important to understand how it works and how to use it safely.
Just treating it like IPV4 with more address space is dangerous though. you need to think differently about security and firewalls as it is as if every device has its own dedicated WAN address and could be open to the internet without you knowing.
Indeed it is good to learn: ipv6.he.net/certification is a free course everybody should take the first 2-3 levels of.
The login credentials you create for that website will allow you to login to their sister site tunnelbroker.net and claim a /48 delegation for your DDNS tunnel, also free, to promote the changeover to v6 from v4, especially for people with dynamic WAN IPS from their ISP and no IPv6.Can confirm that HE course is good. They’ve even sent me a free t-shirt after I’ve completed it.
Nice to meet you, guru!
Okay, so manu of these answers are just plain wrong. In short, you shouldn’t care as the biggest impact will be to network admins. They are the ones who have to configure routing and handle everything else that comes with new addresses. The rest of the world simply doesn’t know or notice whether they are using IPv4 or v6. Business as usual.
If the question is whether you should play with it at home. Sure thing if you have the desire to. It’s the future and only a matter of time before it becomes a reality. Said network admins and ISPs have been delaying the transition since they are the ones who have to work it out and putting your entire user base behind single IPv4 NAT is simpler than moving everything to IPv6.
From network admin perspective, yes it’s worth moving to IPv6 since network topology becomes far simpler with it. Fewer sub-networks, and routing rules to handle those. Less hardware to handle NAT and other stuff. Problem is, they made the bed for themselves and switching to IPv6 becomes harder the more you delay it. Number of users in past 10 years or so has skyrocketed. Easily quadrupled. We use to have home computers with dial-up. Easy enough, assign IP when you connect, release it on disconnect. Then broadband came and everyone is sitting online 100% of the time. Then mobile phones which are also online 100% of the time. Then smart devices, now cars and other devices start having public internet access, etc. As number of users increases, network admins keep adding complexity to their networks to handle them. If you don’t have public IP, just do
tracerouteand see how many internal network hops you have.
