There’s a bunch of advantages. IPv6 can be useful since your devices can have the same IP both internally and externally. No dealing with port forwarding. No split horizon DNS (where you have different DNS entries for internal vs external). No NAT. No DHCP required for client systems (can just use SLAAC to auto-generate addresses). Much simpler routing. It’s a bit faster. Proper QoS.
I used to use Comcast, who actually have very good IPv6 support. They were the first major US ISP to roll out IPv6 to everyone, around 10 years ago. Unfortunately my current ISP doesn’t have IPv6, but they’re aiming to roll it out this year.
A good ISP that supports IPv6 will give you a /64 range. That’s a huge number of IPs, 2^64. Easily enough for every device on your network to have a lot of public IPs. If you use Docker or VMs, you could give each one a public IPv6 address.
When every device on your network can have a public IP, there’s no longer a reason to have private IPs. Instead, you’d use firewall rules for internal-only stuff (ie allow access only if the source IP is in your IPv6 range).
This is how the internet used to work in the old days - universities would have a large IP range, and every computer on campus would have a public IP.
Of course, you’d still have a firewall on your router (and probably on your computers too) that blocks incoming connections for things you don’t want to expose publicly.
old post, but I so wonder why you got downwoted for saying it like it is. a good isp will give you a /56, the minimum best practice. a great isp will give you a /48 you’r router will also participate in the wan /64, but that is just the uplink, and not something that will be used on the lan. www.ripe.net/publications/docs/ripe-690/#4--size-…
wouldn’t /64 still leave you with 64 bits for you to do whatever? Ipv6 has a 128 bit address. If you can do subnets with a small usable portion of 32 bits, then you certainly can with a full 64 bits
The smallest recommended IPv6 subnet is /64. The biggest issue you will encounter is that SLAAC will refuse to work on anything smaller, and it just so happens that Android still doesn’t support DHCPv6 and will be left without a valid address.
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.
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.
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 traceroute and see how many internal network hops you have.
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.
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.
Right. Packets still have to go through your router, assuming that your router has firewall turned on, it goes like this:
Your router receives a packet.
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.
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.
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.
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.
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.
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.
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.
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.
That’s already happened, which is why some ISPs use CGNAT. CGNAT is “carrier-grade NAT” which means the internet provider does NAT on their network.
Only having CGNAT with no IPv6 is a pain since you can’t do any port forwarding. It’s double-NAT which slows things down a bit (you use NAT on your network, then your ISP uses NAT on their network).
Some cloud providers also have IPv6-only servers for cheaper. IPv4 address are still available but the price to acquire them is significantly higher than it used to be.
It’s really common in cellular connections as well as smaller regional ISPs. I work for a rural fiber co-op with about 50,000 members/customers and we do CGNAT for all our members by default because we only have about 36,000 IPs allocated to us. We also have full ipv6 support as well with every customer getting a /56.
To get a big enough block for all our enterprise/business/residential customers to do 1:1 NAT for ipv4 would probably require an entire /16 which costs somewhere in the neighborhood of 2 million dollars last I checked. And even then we would eventually run out because we are constantly expanding to cover rural areas that have been ignored for decades by the big ISPs. Right now if a member needs a static or routable we just charge 10$ a month, and we have enough in reserve for all our members to operating like this likely until the entire internet abandons ipv4.
Honestly I don’t have a good answer for that. The ones who charge a one time fee are honestly being pretty generous (depending on the price you paid) considering there are yearly dues to ARIN/RIPE/APNIC/etc for IP allocations depending on their aggregate block size as well as the fact that IPs are generally very valuable right now, and go up in value depending on the block size.
If they have a legacy registration they also don’t have to pay those dues, though the downside is they don’t get the newer features like RPKI without signing a LRSA/RSA (and therefor paying those dues) and getting their routes certified. Usually doesn’t cause an issue as not many peers drop unvalidated BGP prefixes on IPv4.
That being said, if your ISP has been in the game for decades, they probably have owned their blocks for decades and got them for pennies on the dollar when ARIN and other registries were handing out IP addresses like candy. I know the last /24 my company had to buy cost us somewhere in the neighborhood of $14,000 when it was all said and done, and that was just for 256 IPs.
Eventually IPv4 addresses will become so prohibitively expensive, that is what will eventually push mass IPv6 adoption on the ASN side of things.
Thank you that was really informative. I paid <$50 for my IP address in 2015. My ISP has been around since 1990 so I suppose they may have been one of the lucky companies. Not sure if they do RPKI, first I’m learning of it. Maybe they’re cross subsidizing from other areas of the business. Their monthly fibre fee isn’t the most competitive but the service is reliable and haven’t had anything to complain about.
They are a little behind in speeds though. They only offer 900mbps asymmetrical max, while you can get 2, 4 and 8gbit in my area from other providers. I don’t need that kind of speed so I’m happy for now.
$50 one time is a great price. We charge our members $10 a month if they request a static. We’re also a not for profit coop, so all that money gets either dumped back into network infrastructure and expansion plans, or capital credits for our members.
You’ve very likely already encountered it if you have a device with a SIM card! Most any mobile provider routes via a CGNAT - it’s exceedingly rare for phones to have public IPs.
Not sure which country you’re in, but CGNAT is pretty common in some European countries. ARIN had a larger stockpile of IPv4 addresses than APNIC and RIPE, so CGNAT is less common in the USA and Canada. The US is also generally further ahead in terms of IPv6 rollout compared to other countries. One of the largest ISPs, Comcast, has been IPv6-enabled for over 10 years.
Living in the APNIC region, we are kinda notorious for being the first region to run out of IPv4 addresses.
The top 3 mobile ISPs in my country here have been doing CGNAT since at least 2014. Cable ISPs are limiting public IPv4 according to plans since at least 2017, i.e. if the download speed of your plan is below 200Mbps , you get CGNATed.
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
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.
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
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.
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.
(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. 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)
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.
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.
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.
Doesn’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.
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’m lazy and don’t want to remember more than three digits in an IP address or secure all my devices like they’re publicly routable so I’m sticking with IPv4
The number of short IPv6 addresses is smaller than the number of IPv4 addresses, so that’s defeating the entire purpose of IPv6. Sooner or later you have to start using the long addresses.
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