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Building a Mostly IPv6 Only Home Network
- PaulKeeble 7mo agoI suspect I am going to be running dual stack for at least the next decade, IPv4 switch off feels very far away. I don't think there is much advantage or disadvantage to running IPv4 compared to translation. The current internet doesn't feel ready. I have had less issues with IPv6 this year compared to last so there has been some progress but I am still getting fallbacks to IPv4, some companies don't seem to care much about IPv6 outages currently.
- para_parolu 7mo agoI can’t understand benefits of having ipv6. The only one is public ips but rest is just headache. In my home network I specify disabled v6 everywhere.
- kalleboo 7mo agoWhere I live, the benefit of IPv6 is it's a lot faster than IPv4. All of IPv4 goes through various centralized tunnels and CG-NAT which adds bottlenecks and latency.
- mr_mitm 7mo agoA site-to-site VPN of two previously unrelated local networks is a pure gamble with IPv4. It would be almost straight forward with IPv6.
- wolvoleo 7mo agoYes but these days overlay networks are a way more common practice for that, with their own benefits (overlay IPs are always encrypted)
- baq 7mo agoIt doesn’t matter in home networks, it’s a major pain in the ass if you are a Fortune 500 company and want to set up more intercompany vpn links
- webstrand 7mo agoIPv4 pricing isn't a good enough reason? If all of my devices had nice ipv6 connectivity I could ditch the public ipv4 addresses, but I have to keep them so that my ipv4-only devices can still reach them.
- iknowstuff 7mo agoIpv4 is the headache. What are you talking about, ipv6 is simpler in my experience.
- chungy 7mo agoIPv4 is pretty simple and good for LANs. Nothing wrong with sticking to it.
- iknowstuff 7mo agoMatter requires IPv6
- wolvoleo 7mo agoHuh, I have matter devices working here and IPv6 is off on my router and DHCP. And on home assistant too which does the matter router. Does it use link local or something?
- cesarb 7mo ago> IPv4 is pretty simple and good for LANs. Until the place you're VPNing to happens to use the same RFC1918 network address as your LAN (that is, your LAN is 192.168.10.x and the network on the other side of your work's VPN is also 192.168.10.x). Or either of them use the same RFC1918 network address libvirt is using for its virtual network. Or you want to route between several LANs (for instance, after a company merger) and some of them (but not all) were using the same RFC1918 network addresses. All of this is avoided by using public addresses for LANs, but address scarcity makes that hard with IPv4 (unless it's a legacy LAN from the 1900s which happens to still use public addresses form the pre-NAT era).
- chungy 7mo agoDon't confuse "simple and good" with "flawless" :-) There are indeed only a few private-reserved IPv4 ranges, and almost everyone prefers to keep things memorable and easy to type; you get a lot of 10.0.0.0/24, 192.168.0.0/24, 192.168.1.0/24 as a result. That, and common household routers tend to default to one of these three /24 subnets. (Hardly anyone seems to remember that 172.16.0.0/12 exists, feel free to use that if it happens to work for you.) IPv6 does solve this issue in a few major ways, one of which is the greater expectation to rely on globally routable addresses, of which every one of your devices will have at least one such address. There's also fc00::/7 which is fairly equivalent to the IPv4 private ranges, though to avoid conflicts in random VPNs you should generate a random /64 prefix inside of this, otherwise you run the risk of everyone picking fc00::/64 because it's easy to remember/type (I'm guilty of this myself, but the VPNs I've configured just go into a random 172.16.0.0/12 subnet and no v6 assigned. I have the liberty that I currently don't need/use any VPNs that I haven't personally configured, and that may not hold true in the future.)
- gzread 7mo agoPublic IPs is a huge huge huge benefit. Your connection is also faster because your IPv6 packets don't have to be processed by a centralised CGNAT.
- wolvoleo 7mo agoThat's only if you are behind CGNAT though. My fixed ISP doesn't use it.
- mrsssnake 7mo agoEven without CGNAT you'll only get one IPv4 address forcing a absurd amount of workarounds to be usable, that are mostly hidden in firmwares but sill there.
- Plasmoid 7mo agoYet. Many ISPs are pushing v4 users into CGNAT so they're easier and cheaper to manage. This is a big reason why Netflix and YouTube are on v6. To avoid the cost of service over v4.
- arhue 7mo agoFor home use biggest advantage is that it avoids NAT, which breaks end to end connectivity. Lot of services use hacks to try to mitigate broken connectivity.
- compounding_it 7mo agovideo games
- functional_dev 7mo agoimo one huge benefit is that ipv6 is much easer for hardware to process.. ipv4 headers are messy and change size. ipv6 headers are 40 bytes! routers have less thinking. this visualisation might help to dive deeper - https://vectree.io/c/ipv6 https://vectree.io/c/ipv6
- bigstrat2003 7mo agoPublic IPs are a huge benefit and are enough to justify the switch. And there really aren't any headaches in this day and age with IPv6. Once you set it up it works just fine.
- mwexler 7mo agoFinally. I will now be able to run ~340 undecillion devices on my home network. I'll have the smartest "smart home" on the block.
- dwedge 7mo agoI never understood the rationale of giving out /64 and /48 like candy after what happened with ipv4. I know it's still a massive increase in capacity and I know it makes the networking easier but it seems like we went from something that definitely won't run out (ipv6 addresses) to something that probably won't (number of /48 ranges)
- ndriscoll 7mo ago/48s are "small" enough that we could give ~8 billion people each 35,000 of them and we'd still have ~1.5 trillion (over 300x the size of the ipv4 space) left over. Addresses are basically infinite, but routing table entries (which fragmentation necessitates) have a cost.
- tosti 7mo agoCurrent recommendation (afaict ianant) for ISPs is to give everyone a /56. Not every isp does that, ofc
- boredatoms 7mo agoIf we actually get to the point of address shortages, Either, NATv6 would become a thing, or instead I hope SLAAC would get deprecated and dhcpv6 would become mandatory so we could give out smaller than /64s
- ndriscoll 7mo ago2^64 is 18,446,744,073,709,551,616. That's 18 quintillion. 10^19. There are ~10^10 people on the planet. Each person could have a 10^9 networks (not even devices) before we ran out of /64s.
- 7mo ago
- rao-v 7mo agoI messed with this at one point and gave up when I realized every device would have a permanent externally addressable IP within a block that is basically linked to me (good luck trying to change your IPv6 /48 every month or whatever you get with consumer IP addresses) It’s probably not a big deal and NAT etc. is no protection but it gave me the heebie jeebies.
- icedchai 7mo agoYou know your external IPv4 address rarely changes and also basically linked to you too, right?
- spijdar 7mo ago> your external IPv4 address rarely changes Bad generalization. I'm sure policy about this differs a lot, but my consumer ISP definitely reassigns my home's v4 address periodically. I don't track it closely, but it seems that when my ONT power cycles more often than not it pulls a new v4 address. Now, basing my privacy/security on this would be bad, but to GP's point, if I was using a static v6 block, not only would this address never change, each device in my LAN would have an extra identifier attached to it. External hosts wouldn't merely be able to identify "my house", but traffic from "my phone", "my kid's switch", and "my spouse's phone" would all have distinct addresses. Of course, my ISP doesn't do v6 at all, so there's no dilemma :')
- yjftsjthsd-h 7mo agoThat's also a poor generalization, though. Some ISPs rotate customer subnets, and devices can rotate their randomized IPs.
- spijdar 7mo agoThat's why I specified if one was using a static v6 network. There are several reasons why this might not be true, from ipv6 CGNAT like what cell providers do, to ISP rotation, to randomization in your own network, to NATing from the private network if you wanted. But it does seem like it would be far more likely de facto for an ISP to not randomly rotate v6 networks, except maybe to discourage hosting on consumer connections?
- victorbjorklund 7mo agoWish I could use ipv6. My ISP doesn’t support it (yea, I know tunnels exists but then it’s just more pain than just using ipv4)
- mrsssnake 7mo agoMuch less pain than people wanting to have something you could connect to would experience.
- jcalvinowens 7mo agoDo you actually own that /48? The problem with using the globally routable addresses internally is that your public /48 might change in the future, and and that will force you to change a bunch of internal stuff. I have my router set up to advertise two /64 prefixes on each LAN subnet: one from fddd:deca:fbad::/56* that I use for all internal communication, and one from 2001:5a8:xxxx:xxxx::/56 that is only used for talking to the internet. Every device I've ever tested supports this configuration flawlessly, including linux/apple/windows laptops, apple/android mobile devices, an IoT vacuum, and a 10+ year old VoIP phone. My router is a Linux PC, so I can configure radvd however I want (no GUI, I just edit the configs over SSH). Maybe home routers won't let you do this. * You're really supposed to pick a random prefix in fd00::/8, but uniqueness only matters if you intend to merge networks with somebody else later, I care more about it being easy to remember.
- compounding_it 7mo ago>Do you actually own that /48? In my experience the ISP generally fixes a /64 for each customer. So if in the future you change your ISP, you might want to keep the remaining addresses same while just using a script to replace the preceding /64 address.
- jcalvinowens 7mo agoTypically it's similar to ipv4, they try to assign the same address/prefix for the same MAC/DUID. The most common reason to lose your addresses is replacing your router. Hopefully new routers allow you to set the dhcpv6 DUID somehow...
- compounding_it 7mo agoI haven't experienced this. For me it's statically assigned but my guess is that the PON serial and/or MAC is being used or the customer ID. I think the ISPs have gotten very automated these days and everything seems to be some sort of SDN. It saves lot of labour hours in troubleshooting like customer forgetting their wifi passwords to their routers.
- tonymet 7mo agoI attempted a similar effort, and found my router had critical ipv6 vulnerabilities including binding the admin and SSH to the WAN on ipv6 (not on ipv4) , and disabling IPv6 firewall altogether so the LAN services were exposed to the internet. I had the vendor publish their GPL drop, and their upstream vendor did not even have IPv6 support in the product ( the firmware init scripts & admin UI) . So the IPv6 support in the finished product was a rushed copy-paste of IPv4 setup. I encourage full black box testing of your IPv6 setup, as IPv6 is not in the critical path for QA or consumers, so vulns can persist for years.
- tosti 7mo agoFor my own networks I use the private range internally (fd00::/8). That way the addresses remain the same when we move or change the pipe to a bigger one. Also, they can be routed, just not on the Internet. It's easy to join remote networks over wireguard and there's plenty of room for experimentation.
- wolvoleo 7mo agoWhy though? What's the problem with ipv4? I find it much simpler for troubleshooting etc to have simple IPv4 addresses. But cool that it can be done :) I've switched off IPv6 on my router anyway, I haven't yet needed it. My provider didn't offer it last time I checked but when they do enable it I don't want it suddenly popping up against an untested router configuration.
- mrsssnake 7mo agoThis video summarizes it nicely https://www.youtube.com/watch?v=42Hy4JtBeQA https://www.youtube.com/watch?v=42Hy4JtBeQA
- mxuribe 7mo agoThanks for sharing this! Every few years, i forget the "why" advantage of IPv6. :-)
- dijit 7mo agoI don't know your background, but I find that the people who feel that there's nothing wrong with IPv4 have never done any work with UPNP or NAT. For them it's always "just worked" and they don't recognise what pain has gone into trying to keep it working well despite our usage of it bordering abusive. NAT is the devil. If anyone replies to this with the myth that NAT is a security mechanism I will firmly, yet politely, point them to a network development course because they don't know what they're talking about and I'm sick of hearing it. It's not true, I will not entertain this falsehood anymore.
- wolvoleo 7mo agoI do work with NAT, but the stuff I use does hole-punching pretty transparently. I run 2 VPSes to facilitate this. I don't use UPNP, I have it explicitly disabled everywhere (too much malware that tries to leverage it) And yes I know that NAT has the same effect as a "deny all inbound" on IPv6. Which is something I would set there too if I did use IPv6 so I'd still have to do hole-punching anyway.
- 7mo ago
- lucasay 7mo agoIPv6 isn’t that compelling on a simple home network, but avoiding NAT and easier end-to-end connectivity are pretty real advantages.
- boredatoms 7mo agoIt looks like an in-kernel replacement for jool is coming https://lore.kernel.org/netdev/20260319151230.655687-1-ralf@mandelbit.com/ https://lore.kernel.org/netdev/20260319151230.655687-1-ralf@...
- yjftsjthsd-h 7mo agoThat's fantastic news; there weird friction around NAT64 on Linux has been a real pain point.
- mrsssnake 7mo agoDual stack IPv4+IPv6 is still the easiest, but at least the author learned a lot and it helps finding issues in software.
- thebeardredis 7mo ago"mostly" (...) "only"
- yjftsjthsd-h 7mo ago? I thought they did still support v4? > This is where DHCPv4 Option 108 comes into the picture. This simply tells the client that IPv6 only mode is preferred. Clients that do not honor this will get a IPv4 address as normal. Those who do have an option can setup 464XLAT to handle IPv4 literals and disable IPv4 addresses.
- aap_ 7mo agoI'd be so much more interested in ipv6 if ISPs would just hand out a stable prefix. as it is ipv6 makes very little sense to me
- bigstrat2003 7mo agoThat depends very much on your ISP. Mine (Comcast) does give out a stable prefix. It's not guaranteed to be static forever, but in practice it never changes unless I release it from my router or on the rare occasion they replace their network hardware.