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Show HN: A Short IPv6 Guide for Home IPv4 Admins

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Re: Show HN: A Short IPv6 Guide for Home IPv4 Admins

#31

Post by hot_gril »

redundantly wrote: post #3

It's weird. Personally I've yet to make the jump to IPv6 because it seems too complex, doesn't make sense, so I don't want to spend the mental effort learning it when I have no need to switch. However, looking decades back I realise I felt the same way when first learning about and working with networks. Nothing about it is intuitive. It's all complex, until it isn't through repetition and familiarity. That said, I s…

I'm ok with the opinionated kind of ipv6 this guide puts forth. There are too many other ways to use it that have problems.

Re: Show HN: A Short IPv6 Guide for Home IPv4 Admins

#32

Post by Latty »

ThePowerOfFuet wrote: post #7
Latty wrote: post #4

Earlier quoted context omitted.

I believe the point the post is making is that there are some runs of zeros that can't be condensed, not that you can condense multiple runs in a single address.

All runs can be, but you can pick only one, so you should do pick the longest one.

To be clear, I think the technicality the author is alluding to is that it is not all runs, because some runs of zeroes are significant, you can't condense the zeroes in "ff00:..." for example, for obvious ambiguity reasons. I believe using "some" was just a way to allow for that while not describing the rules in detail.

Re: Show HN: A Short IPv6 Guide for Home IPv4 Admins

#33

Post by philsnow »

anthropodie wrote: post #23
philsnow wrote: post #21

How does this: > With IPv4, when your router connects to your ISP, you get one public address for the WAN, and you use a picked private address like 192.168.0.0/24 for your LAN. With IPv6, since you want a globally routable address for hosts on your LAN also , you need to ask the ISP for a routable prefix. jive with this: > You want to use these ULA for all your LAN communication. If you want to reach your printer or…

> Why have globally-routable IPv6 addresses if you're not going to use them? Because globally routable addresses are not static. Your prefix may change.

I guess I mean, the gist only motivates the use of globally-routable addresses for externally accessible services. If a particular service/device isn't going to be accessed externally, there's no need to give it one.

Re: Show HN: A Short IPv6 Guide for Home IPv4 Admins

#34

Post by throw0101c »

philsnow wrote: post #26
philsnow wrote: post #21

How does this: > With IPv4, when your router connects to your ISP, you get one public address for the WAN, and you use a picked private address like 192.168.0.0/24 for your LAN. With IPv6, since you want a globally routable address for hosts on your LAN also , you need to ask the ISP for a routable prefix. jive with this: > You want to use these ULA for all your LAN communication. If you want to reach your printer or…

Ah: > For your externally visible servers, use dyndns type service, and update it with the globally routable address. Residential internet will rotate the prefix over time (the prefix is dynamic), so this is the same as running a server on a residential dynamic IPv4. > For firewall, drop all inbound packets by default. For externally visible servers, you can match the last 64 bits only, so that changing prefixes don’…

> Since I don't (currently) want anything at all to be generally externally accessible, it seems that I could just use ULAs for the LAN machines and not assign them globally-routable addresses..... but at that point I guess there's no reason to be configuring IPv6 at all (?), which is exactly the current state of my LAN.

You can have ULA address and globally-routable addresses (GRA) at the same time: they are not mutually exclusive. IPv6 was designed to (possibly) have multiple addresses on the same interface, while with IPv4 this is a (bit of a) 'strange' configuration (to have multiple addresses/aliases).

So go ahead and assign a ULA if you wish, but your system will also just get an address which is globally addressable (but not globally reachable address because of firewalls).

Re: Show HN: A Short IPv6 Guide for Home IPv4 Admins

#35

Post by alsetmusic »

I've just got back into building a homelab after a multiyear break. I think I last worked on such a project in 2017. In the time between then and now, I still don't know why I would want to utilize IPv6 on my home network. And my network is necessarily more complicated than most users by extension of the homelab (switches, hypervisors, VM's, etc).

I imagine I might be able to go looking for an answer to why I'd want this, but I would have expected the case to have been made casually by now if it had any utility in my home. I never stopped reading technology and computing sites during my sabbatical, though they did become more mainstream. Yet I still have no clue why I'd want this on a home network. This seems like a solution in need of a problem (in the home – I'm not discounting the utility on a global scale).

Re: Show HN: A Short IPv6 Guide for Home IPv4 Admins

#36

Post by khrbtxyz »

zdw wrote: post #15

If you want to run authoritative DNS on your home network and have AAAA lookups for local machines, how do you go about this? Assign the DNS entry just to the ULA of each host?

Returning both the ULA and global addresses should be okay. This is what my OpenWRT router does without any special setup. wk1 is one of my local machines.

  $ dig +short wk1 AAAA @192.168.1.1
  2601:646:...
  fd7c:b0fd:fd6a:1::ba5

Re: Show HN: A Short IPv6 Guide for Home IPv4 Admins

#37

Post by devman0 »

hot_gril wrote: post #17

I'm a home ipv4 admin. What I or someone similar would need is the last part that shows how you set up a basic network with some local addresses I care about and a few I want to expose publicly. It's nice that the guide includes the concepts, but the first thing anyone will want to do is just make it work. Step 2 says to set up ULAs. Are these static or dynamic? It says "don't pick numbers." If dynamic, how does step…

ULAs are generally static, almost all IPv6 unicast addresses are static though sometimes you may have "temporary" addresses via privacy extensions on hosts, those should only be for egress traffic out to the internet, intra-lan traffic should use ULAs.

Your ISP can change your prefix delegation, in practice this shouldn't happen often, but if your in a situation where you need to deal with it frequently on the same network (running a service with a short lived delegation) DDNS still works for IPv6.

Re: Show HN: A Short IPv6 Guide for Home IPv4 Admins

#38

Post by move-on-by »

wmf wrote: post #12
imoverclocked wrote: post #5

> After your router connects to your ISP, the router can ask for prefix delegation. Some providers (eg: Starlink, when I last checked and a Calyx WiFi hotspot) will only advertise a prefix. I was forced to figure out a way to bring the /64 that is in front of my router (Linux iptables) and expose it to a LAN behind my router. It looks something like [1] Depending on your setup, there may be an easier solution. [1] ht…

It sounds like you're talking about running a router behind a router which you should try to avoid. If you want to run your own router you should try to put your modem/dish in passthrough mode. Once you do that Starlink works fine.

This assumes your ISP provided modem isn’t straight up user hostile and provides a pass through mode. I’m convinced t-mobile’s awful home internet modem/router is intentionally designed to make using your own router difficult and specifically only provides a /64 prefix delegation to prevent any router-behind-router setups from getting globally routed IPv6 addresses. Not to mention no port forwarding capabilities.

Re: Show HN: A Short IPv6 Guide for Home IPv4 Admins

#39

Post by anthropodie »

labcomputer wrote: post #16
mannyv wrote: post #6

How do you run a DNS server when your address isn't technically static? How do clients discover the DNS server in a SLAAC environment?

1. You create a ULA prefix (fc00:/7) on your local network. See https://en.m.wikipedia.org/wiki/Unique_local_address 2. Then you have your router advertise that prefix. 3. Then you have your DNS server pick a non-temporary address within that prefix (either manually set it, or let the OS pick one). 4. Then you tell your router to advertise that address as the DNS server in the RA. Depending on how you have your netwo…

If your router does not support ULA configuration like in my case you can make a device like raspberry pi to advertise ULA. You can refer this thread for that configuration https://www.reddit.com/r/ipv6/comments/1af0r2v/using_rpi_to_...

Re: Show HN: A Short IPv6 Guide for Home IPv4 Admins

#40

Post by m463 »

redundantly wrote: post #3

It's weird. Personally I've yet to make the jump to IPv6 because it seems too complex, doesn't make sense, so I don't want to spend the mental effort learning it when I have no need to switch. However, looking decades back I realise I felt the same way when first learning about and working with networks. Nothing about it is intuitive. It's all complex, until it isn't through repetition and familiarity. That said, I s…

I think ipv4 is way more manageable.

One set of firewall rules, easy to view ip addresses, machines don't leak.

I would put the extra braincells to work learning vlans. putting machines in jail is a liberating experience.

You can also learn to use privoxy to control IF machines have internet access, who they talk to and when.

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