IPv6 has been the future of the internet for so long that it is tempting to assume it will never actually arrive. In reality your business almost certainly already uses it, often without anyone deciding to, while IPv4 quietly costs you money and adds complexity behind the scenes. This is not a debate about which protocol is better in theory; it is a practical look at what changes for an SME, what genuinely does not, and the handful of places where the difference between the two shows up on your bill or in your support tickets.
The same job, two different address books
Both IPv4 and IPv6 do the same fundamental thing: they give every device an address so traffic can find it. The difference is how many addresses exist. IPv4 uses the familiar four-number format like 192.168.1.10 and offers roughly four billion addresses in total, which sounded limitless in the 1980s and ran out years ago. IPv6 uses much longer addresses and offers a number so vast it is effectively inexhaustible, enough for every device humanity will ever build.
That single difference, address scarcity versus abundance, is the root of almost everything else. IPv4's shortage forced the internet to invent workarounds to share addresses, and those workarounds are where the cost and complexity live. IPv6 removes the scarcity, which removes the need for the workarounds, but it also means relearning a few habits. Neither replaces the other overnight; for years to come you will run both side by side, which is called dual-stack.
Why IPv4 still costs you money
Because IPv4 ran out, public IPv4 addresses became a traded commodity with a real market price. If your business needs its own block of public addresses, you now lease or buy them, and providers increasingly pass that scarcity on as a line item. The shortage also forced widespread use of NAT, network address translation, where many devices share one public address. NAT works, but it adds a layer that complicates remote access, some applications and any service you want to host yourself.
The practical upshot for an SME is that IPv4 is the protocol of small surcharges and small frictions: a charge for a static address, an extra hop of NAT to reason about, port forwarding to configure, and the occasional application that misbehaves behind shared addressing. None of it is fatal, and most businesses live with it happily, but it is worth understanding that the costs are a symptom of scarcity, not of the technology being bad.
- •Public IPv4 addresses are scarce and now carry a market price
- •NAT lets many devices share one public address but complicates hosting and remote access
- •Static IPv4 addresses are often a paid add-on from providers
- •Carrier-grade NAT at the ISP can break some peer-to-peer and inbound services
What IPv6 actually changes for an SME
The headline benefit of IPv6 is that every device can have its own globally reachable address, so the NAT workaround largely disappears. In principle that makes direct connections, remote access and hosting simpler, and it removes a class of awkward problems. IPv6 was also designed with modern needs in mind, so address auto-configuration and routing are cleaner. For a business, the most visible change is usually nothing at all: browsing, email and cloud apps work identically over IPv6.
Where it does demand attention is security and tooling. Because IPv6 gives devices public addresses by default, your firewall must be configured to protect them; an unmanaged IPv6 stack can quietly expose devices that IPv4's NAT happened to hide. Some older equipment, monitoring tools or internal applications also assume IPv4 and need checking. So IPv6 is not free to adopt well, but the work is configuration and review, not a rip-and-replace.
Dual-stack: why you already run both
The reality on the ground is that the internet runs IPv4 and IPv6 together. Most modern operating systems, phones and broadband connections enable IPv6 automatically and prefer it when both are available, falling back to IPv4 when they must. That is dual-stack, and it is why you are very likely using IPv6 today without having switched anything on. It is also the sensible migration path: you add IPv6 alongside IPv4 rather than cutting over.
Dual-stack means the question is rarely IPv4 or IPv6 as an either/or choice. It is whether your IPv6 is configured deliberately, secured and monitored, or whether it is on by accident and unmanaged. The risk is not running both; it is running one of them blind. Treating the address layer as part of your wider network security is what turns dual-stack from a hidden liability into a non-event.
So what should a business actually do?
For most SMEs the right posture is calm and deliberate. You do not need to chase an IPv6 migration for its own sake, and you should not assume IPv6 is absent just because nobody enabled it. Find out what your connection and equipment already do, make sure your firewall protects IPv6 to the same standard as IPv4, and check that any self-hosted service or remote-access setup behaves on both. That is most of the job.
If you are buying new connectivity, specifying servers or designing anything that faces the internet, treat IPv6 support as a requirement and budget the IPv4 surcharges honestly. The protocols are not a religious choice; they are two tools you will keep using together for years. The businesses that handle this well are simply the ones who decided how their addressing works on purpose, rather than inheriting it by default.