except for nor using it at all, of course.
So I want to make my homelab IPv6 ready, because I have too much free time, i guess. There are two decisions that I’m currently unsure about:
- ULA or not. Do you have local only addresses or do your clients communicate using the global IPv6 address? Does not using ULAs work without a static IP from the ISP?
- DHCPv6 or is SLAAC enough?
For each question both options seem to be possible and I’m interested in your experience
Cheers
My provider doesn’t provide IPv6, but I rented a server in a data center, bought a subnet, and tunneled it home via WireGuard. So the scheme is roughly: VPS (fd00:1::/64) <-> (fd00:1::/64) Home router (realv6/64) <-> Home network
Router configuration:
/etc/sysctl.d/10-ipv6-privacy.conf
net.ipv6.conf.all.use_tempaddr = 0 net.ipv6.conf.default.use_tempaddr = 0 net.ipv6.conf.all.forwarding = 1 net.ipv6.conf.default.forwarding = 1/etc/radvd.conf
interface br0 { AdvSendAdvert on; MinRtrAdvInterval 3; MaxRtrAdvInterval 30; AdvManagedFlag on; # M=1 → Address via DHCPv6 AdvOtherConfigFlag on; # O=1 → Additional options via DHCPv6 # SLAAC is still possible for Android prefix realv6::/64 { AdvOnLink on; AdvAutonomous on; # Allow SLAAC }; RDNSS realv6::1 { AdvRDNSSLifetime 1800; }; DNSSL home.lan { AdvDNSSLLifetime 1800; }; };/etc/kea/kea-dhcp6.conf
{ "Dhcp6": { "interfaces-config": { "interfaces": [ "br0" ] }, "lease-database": { "type": "memfile", "persist": true, "lfc-interval": 86400, "name": "/var/lib/kea/dhcp6.leases" }, "renew-timer": 21600, "rebind-timer": 43200, "preferred-lifetime": 43200, "valid-lifetime": 86400, "subnet6": [ { "id": 1, "subnet": "realv6::/64", "interface": "br0", "pools": [ { "pool": "realv6::1000 - realv6::ffff" } ], "option-data": [ { "name": "dns-servers", "data": "realv6::1" }, { "name": "domain-search", "data": "home.lan" } ] } ], "loggers": [ { "name": "kea-dhcp6", "output-options": [ { "output": "stdout" } ], "severity": "WARN" } ] } }And of course, iptables is necessary. Something like: /etc/iptables/ip6tables.rules
# Generated by ip6tables-save v1.6.0 on Thu Sep 8 13:29:11 2016 *nat :PREROUTING ACCEPT [0:0] :INPUT ACCEPT [0:0] :OUTPUT ACCEPT [0:0] :POSTROUTING ACCEPT [0:0] COMMIT *filter :INPUT DROP [0:0] :FORWARD DROP [0:0] :OUTPUT ACCEPT [0:0] #BASE INPUT -A INPUT -i eno1 -j DROP -A OUTPUT -o eno1 -j DROP -A INPUT -i lo -j ACCEPT -A INPUT -i br0 -j ACCEPT -A INPUT -p ipv6-icmp -j ACCEPT -A INPUT -m state --state RELATED,ESTABLISHED -j ACCEPT -A FORWARD -i eno1 -j DROP -A FORWARD -i br0 -j ACCEPT -A FORWARD -m state --state RELATED,ESTABLISHED -j ACCEPT -A FORWARD -p ipv6-icmp -j ACCEPT COMMITJust static IP, since I have a static subnet delegated by my provider, on a shitty cable modem.
I can’t get IPv6 in any worthwhile form from my ISP. IMHO IPv6 isn’t any more useful than IPv4 if you only have ULA. And NAT is not as well supported since it wasn’t intended to even be really necessary for example. So even if you are starting from scratch or just using it internally, there are some disadvantages to implementing it over just sticking with IPv6. But if your ISP actually provides IPv6 it might be worth it as long as your devices all support it. But otherwise you’re going to need to set up IPv4 in addition, anyway, so you’re just going to create problems for no good reason, IMHO.
Dual stack setups are not an issue unless your router doesn’t support it or your ISP sucks.
I don’t use IPv6 on my lab. They been screaming to the bleachers since like 2010 that IPv6 is right around the corner due to lack of addresses, and I’ve still seen no real reason to want to adopt for it.
My current provider doesn’t even support it… so why should I?
In fact when I was in college taking classes on IPv6 we were told it would be everywhere next year.
This was 1994. Lol
Personally I don’t like it because it’s too overengineered for me. They should have added 2 bytes to IPv4 and called it a day. That means we would have had the address space of 65536 internets. Really plenty. IPv6 has too much space.
My current provider doesn’t even support it…
In what kind of godforsaken backwater do ISPs that don’t support IPv6 still exist!?
The largest of the 3 carriers in Canada.
Bell.
Does not support ipv6.
I didn’t know that Canada was basically Mordor…
Switzerland, we have the best and worst of both worlds. 25GBit Fiber home connections for less than 100 USD per month and ISPs that only support IPv4.
Which fiber provider doesn’t support IPv6? I thought it was only Swisscom mobile and its subsidiary’s which don’t support it (though from what I heard, even that is in testing now)
Small former Gemeinschaftsanntenne in my town and surrounding villages, I don’t wanna dox myself so can’t tell you the name. They probably have anywhere between 10-20k customers only. But afaik they are just one of many IPv4 only ISPs in Switzerland.
Yea that was similar to my response when I figured I would look into it a few years back. No ipv6 and no ip address rotation unless its offline for more than 24h, which makes thing simple
Blocked by my ISP. So I have it all blocked.
Same here, my ISP is IPv4 only so I have it disabled on my router.

Stock Asus or Merlin?
Don’t use ULA, those are non internet routable addresses so they will never use v6 for internet things. Use the range assigned from your ISP.
SLAAC. Because Android has one ass of a dev who refuses to include DHCPv6You can use both at the same time and it is useful to have ULA if your ISP changes your assigned prefix.
This is what I do. I haven’t seen a reason to change it as of yet.
I use IPv6 local only. Everything else is IPv4. Reason being, my commercial VPN does not support IPv6 and I have reservations about leakage. My ISP already ships with IPv4 & IPv6.
I use ULA for my WireGuard tunnels, otherwise it’s all public IPv6 (mostly lightly firewalled).
I’m fine with SLAAC, even for servers. I just manually update my DNS with the server addresses when I set them up.
For me, every subnet (except internal only ones) have a global IPv6 prefix, including my Wireguard tunnels. I’ve got a mix of statically assigned and SLAAC. I think I’ve setup DHCPv6 too but it either doesn’t work or nothing uses it.
ISP issues a prefix that I delegate.
Also delegate an ULA prefix, intended for stake local addresses but d actually just use ipv4 for those (also had difficulty getting ipv6 to work with microk8s and multus due to inexperience).
SLAAC.
My setup is a pile of kludges built on top of each other over the last two decades.
I started with ULAs distributed through DHCP, connected to named, which allows hosts do declare their own name and let me access local services as though I had a real domain.
My ISP eventually started supporting IPV6, but only assigned /128, so the ULAs got NAT-6ed out to the real world.
I eventually learned how to request prefix delegation from the ISP and set up SLAAC.
So now, my PIv6 clients have a) their link-local address, b) the ULA, c) a “privacy” SLAAC, and d) a unique SLAAC. All my internal services still refer to the ULAs.
I don’t think I’d recommend this system for someone setting up from scratch. The easiest thing would be to go with SLAAC, if you can get prefix delegation, and set your DNS/pihole to send the unique-SLAAC address of any servers you run.
The only systems with ip6v in my network are Wi-Fi devices and my public-facing reverse proxy. I use a prefix delegated by my ISP.
All of my non-public servers have ipv4 only.
I use global addresses for everything. ULA is the equivalent of the private networks like 10.0.0.0/8 on IPv4. It doesn’t need a static IP. ULA will work without any internet connection. If you run an IPv6 only network, it would be a good idea to set up ULA so you can access your local devices if the internet goes down.
I only use SLAAC on my network because DHCPv6 is not well supported. My router does use DHCPv6 to get a prefix from the ISP though.
set up ULA so you can access your local devices if the internet goes down
your router should retain its address even if the external connection goes down.
DHCPv6 is not well supported
Androids get SLAAC, everybody else can have a nice, readable, stable, firewall-openable suffix.
SLAAC with ISP-provided prefix. Everything that wants an IPv6 address gets one and I’ve got my firewall set to block pretty much all in-bound traffic other than SSH. It’s nice being able to SSH directly to something rather than using a jump host or VPN.
I also use ULA because NFS mounts over IPv6 on the global addresses would hang/timeout every time the SLAAC address rotated which is frequent due to privacy extensions.
I live in spain so the main ISP is well provided with IPv4 blocks and have zero incentive to deploy IPv6 outside of mobile networks. So the IPv6 deployment here is like 3% and I don’t have access to it 🫠
Until very recently, I exclusively used the /56 prefix I get from my ISP exclusively. This is still relatively annoying in my case as this prefix changes at least daily for some reason. Clients get their IP via SLAAC.
I’ve added ULA literally less than a week ago as I have a local reverse proxy I want to handle both local and external request, in both v6 and v4. Obviously more hosts should be accessible from local clients. But I can’t tell local clients apart except by IP, and since the prefix is unstable this would require some sort of hook to update the proxy with that new prefix (might be possible, but seems like a real hassle). So here we are.











