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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

#61

Post by yjftsjthsd-h »

spijdar wrote: post #54
icedchai wrote: post #26

Earlier quoted context omitted.

You know your external IPv4 address rarely changes and also basically linked to you too, right?

> 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…

That's also a poor generalization, though. Some ISPs rotate customer subnets, and devices can rotate their randomized IPs.

Re: Building a Mostly IPv6 Only Home Network

#63

Post by simoncion »

jcalvinowens wrote: post #19

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 t…

> Do you actually own that /48?

Well. From TFA:

  So I decided to use Free Range Cloud service provider to lease a /48, which cost me around C$10/year. I also used their tunnel service to then route this over to me.
The link embedded in the pull quote is [0], which isn't maximally helpful, but it's useful. Approximately 60 seconds of poking around there brings us to [1], which quotes a "ARIN - /48 IPv6 lease ... Use on our network or yours" for $8/year with a $2 setup fee. That sounds a lot like what's mentioned in TFA.

So. You tell me?

[0] https://freerangecloud.com/>

[1] https://freerangecloud.com/products.php>

Re: Building a Mostly IPv6 Only Home Network

#64

Post by yjftsjthsd-h »

jcalvinowens wrote: post #53
uyzstvqs wrote: post #45

Earlier quoted context omitted.

Ideally it'll be standard that your DHCP will assign you both an internet IP from your ISP-provided prefix (dynamic or static), and private IP from a ULA prefix, which can be made static through address reservation.

Don't use DCHPv6 at home. I tried: you will hate your life, lots of stuff doesn't support it. Android specifically has zero support for it, google says it never will. Use SLAAC. It just works.

How do you handle internal DNS? I'd really like `curl http://mylaptop.internal` (or so) to work; that's easy with DHCP.

Re: Building a Mostly IPv6 Only Home Network

#65

Post by cesarb »

chungy wrote: post #13
iknowstuff wrote: post #12

Earlier quoted context omitted.

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.

> 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).

Re: Building a Mostly IPv6 Only Home Network

#66

Post by yjftsjthsd-h »

thebeardredis wrote: post #62

"mostly" (...) "only"

? 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.

Re: Building a Mostly IPv6 Only Home Network

#67

Post by simoncion »

jcalvinowens wrote: post #53
uyzstvqs wrote: post #45

Earlier quoted context omitted.

Ideally it'll be standard that your DHCP will assign you both an internet IP from your ISP-provided prefix (dynamic or static), and private IP from a ULA prefix, which can be made static through address reservation.

Don't use DCHPv6 at home. I tried: you will hate your life, lots of stuff doesn't support it. Android specifically has zero support for it, google says it never will. Use SLAAC. It just works.

I'm pretty sure that you can use both. RAs even have bits to indicate if one is supposed to autoconfigure, [0] hit up a DHCPv6 server for some or all configuration, [1] or both. radvd refers to them as AdvAutonomous and AdvOtherConfigFlag/AdvManagedFlag, respectively.

[0] https://datatracker.ietf.org/doc/html/rfc4861#section-4.6.2>

[1] https://datatracker.ietf.org/doc/html/rfc4861#section-4.2>

Re: Building a Mostly IPv6 Only Home Network

#68

Post by simoncion »

jcalvinowens wrote: post #19

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 t…

> * 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.

If you don't care about collision resistance, why didn't you pick fd00:: ? That's way easier to remember than that jumble of letters you selected. It's actually my go-to subnet when someone claims that local-only IPv6 addresses are "hard to remember". fd00::1 is notably shorter than 10.0.0.1.

Re: Building a Mostly IPv6 Only Home Network

#69

Post by spijdar »

yjftsjthsd-h wrote: post #61
spijdar wrote: post #54

Earlier quoted context omitted.

> 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…

That's also a poor generalization, though. Some ISPs rotate customer subnets, and devices can rotate their randomized IPs.

That'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?

Re: Building a Mostly IPv6 Only Home Network

#70

Post by retatop »

simoncion wrote: post #67
jcalvinowens wrote: post #53

Earlier quoted context omitted.

Don't use DCHPv6 at home. I tried: you will hate your life, lots of stuff doesn't support it. Android specifically has zero support for it, google says it never will. Use SLAAC. It just works.

I'm pretty sure that you can use both. RAs even have bits to indicate if one is supposed to autoconfigure, [0] hit up a DHCPv6 server for some or all configuration, [1] or both. radvd refers to them as AdvAutonomous and AdvOtherConfigFlag/AdvManagedFlag, respectively. [0] https://datatracker.ietf.org/doc/html/rfc4861#section-4.6.2 > [1] https://datatracker.ietf.org/doc/html/rfc4861#section-4.2 >

This is exactly what I do. Almost everything has a nice DHCPv6 address so that I can actually remember the ULA + the suffix, but then for the two devices on my network that don't do DHCPv6 they get a SLAAC. One oddity though is that it means most devices on my network have both a SLAAC and a DHCP-provided one, since I wasn't able to be able to get it to prioritize a DHCP. Combine that with them having both ULA addresses and public addresses and some stuff on my network have way more addresses than you'd expect
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