IPv4 still runs most of the internet. IPv6 is the long term plan. For a homelab, the right answer for when to implement IPv6 is often “not yet”. Here is a clear way to think about it.

What IPv4 is

IPv4 uses 32 bit addresses. That is about 4.3 billion unique addresses. We ran out on paper years ago, so networks use private ranges inside and share one public address at the edge using NAT.

What that means at home

• Private addresses inside, one public address outside
• Port forwarding or a reverse proxy if you expose services
• NAT breaks true end to end, but it works and is familiar

What IPv6 is

IPv6 uses 128 bit addresses. That is an enormous space. Devices can have globally routable addresses and also link local addresses for the LAN. Hosts can self configure using router advertisements (SLAAC) or get addresses via DHCPv6.

Key traits

• Huge address space and no need for NAT in most designs
• Router advertisements help hosts configure themselves
• Neighbor Discovery and multicast replace ARP and broadcast
• Privacy extension addresses rotate to reduce tracking

IPv4 vs IPv6 at a glance

• Address size: 32 bit vs 128 bit
• Addressing model: private plus NAT vs mostly global with local scopes
• Discovery: ARP and broadcast vs Neighbor Discovery and multicast
• Config: DHCPv4 vs SLAAC and DHCPv6
• DNS: A records vs AAAA records
• Security posture: NAT often hides hosts vs global reachability that depends on firewall rules

Why IPv6 adoption is still uneven

• NAT stretched IPv4 farther than anyone expected, so many networks never felt pain
• Many ISPs still do not deliver native IPv6 or only do so on some plans
• Dual stack doubles the moving parts to monitor, log, and secure
• Legacy gear, tools, and habits are IPv4 first
• Fear of exposing hosts globally without a careful firewall plan
• Training and docs lag in some shops, so teams avoid changes that do not unlock clear wins

Should you enable IPv6 in a homelab

Good reasons to wait

• Your ISP does not provide IPv6 today
• Everything you run works fine on IPv4 and you do not publish services to the internet
• You prefer a simpler firewall and monitoring setup

Good reasons to enable it

• You want true end to end reachability for learning or specific apps
• Your ISP delegates a prefix and you want to experiment with SLAAC, DHCPv6, and modern firewalling
• You plan to measure and improve dual stack performance

A middle path

• Try IPv6 in an isolated VLAN for learning
• Use a ULA prefix (fd00::/8) for internal only experiments
• Keep default inbound drops on IPv6 until you write explicit allows

Safe rollout notes

• Confirm your ISP gives you IPv6 (often via prefix delegation) before changing production networks
• Keep dual stack simple: same firewall posture on v4 and v6, default deny inbound on both
• Update DNS with AAAA records only when a service is ready for v6
• Watch logs and flow data to verify which stack clients prefer

What I run today

I keep the lab IPv4 only until native IPv6 is available from the ISP or a project needs it. The extra moving parts of dual stack do not buy me much yet. When it does, I will stage it in a test VLAN first and then roll it out with a clear firewall plan.