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Building a Mostly IPv6 Only Home Network

varunpriolkar.com

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Re: Building a Mostly IPv6 Only Home Network

#11

Post by ndriscoll »

dwedge wrote: post #8
mwexler wrote: post #6

Finally. I will now be able to run ~340 undecillion devices on my home network. I'll have the smartest "smart home" on the block.

I 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)

/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.

Re: Building a Mostly IPv6 Only Home Network

#13

Post by chungy »

iknowstuff wrote: post #12
para_parolu wrote: post #3

I 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.

Ipv4 is the headache. What are you talking about, ipv6 is simpler in my experience.

IPv4 is pretty simple and good for LANs. Nothing wrong with sticking to it.

Re: Building a Mostly IPv6 Only Home Network

#16

Post by tosti »

ndriscoll wrote: post #11
dwedge wrote: post #8

Earlier quoted context omitted.

I 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)

/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.

Current recommendation (afaict ianant) for ISPs is to give everyone a /56. Not every isp does that, ofc

Re: Building a Mostly IPv6 Only Home Network

#17

Post by boredatoms »

dwedge wrote: post #8
mwexler wrote: post #6

Finally. I will now be able to run ~340 undecillion devices on my home network. I'll have the smartest "smart home" on the block.

I 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)

If 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

Re: Building a Mostly IPv6 Only Home Network

#18

Post by flumpcakes »

dwedge wrote: post #8
mwexler wrote: post #6

Finally. I will now be able to run ~340 undecillion devices on my home network. I'll have the smartest "smart home" on the block.

I 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)

In IPv6 the smallest 'subnet' is /64 if I recall correctly.

It's weird having a subnet size equal to a complete IPv4 Internet worth of IPv6 Internets but I believe the rationale was that you would never in practise run of out IPs in your subnet. A lot of Enterprise IPv4 headaches are managing subnets that are not correctly sized (organic growth, etc.). IPv6 is always routable for the same reason (companies reusing RFC1918 making connecting networks a pain).

There are different headaches with IPv6 - such as re-IPing devices if they move subnet - i.e. move physical location, or during a failover etc.

I'm not sure what the best practise there is as many enterprises don't use IPv6 internally. In my experience anyway.

Re: Building a Mostly IPv6 Only Home Network

#19

Post by jcalvinowens »

Do 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.

Re: Building a Mostly IPv6 Only Home Network

#20

Post by ndriscoll »

boredatoms wrote: post #17
dwedge wrote: post #8

Earlier quoted context omitted.

I 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)

If 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

2^64 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.
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