Why does my phone show both an IPv4 and an IPv6 address?

Because it has both at once. Most networks today are dual-stack, meaning every device picks up a private IPv4 address from your router's DHCP pool and a separate IPv6 address at the same time. Your phone uses whichever one the app or site it's talking to supports, and you don't see it switch.

Will turning off IPv6 fix a network problem?

Sometimes, for specific symptoms like a VPN that won't route through it correctly, but it's a troubleshooting step, not a default fix. Turning IPv6 off on a router that's otherwise working normally doesn't speed anything up and can break apps or games that already rely on it.

Does IPv6 mean I don't need NAT anymore?

On the IPv6 side, often yes, since there are enough addresses for every device to have its own public one. In practice your router still runs IPv4 with NAT for everything that needs it, and most home routers firewall inbound IPv6 by default too, so the day-to-day behavior doesn't change much.

IPv4 vs IPv6 on your home network, and whether you need to care

TL;DRMost home networks run IPv4 and IPv6 at the same time by default, and there's rarely a reason to change that. Here's what actually differs.

Short answer: IPv4 and IPv6 are two versions of the addressing system the internet uses, and most home networks run both at the same time. IPv4 is the older, shorter format (like 192.168.1.1) and the one your router still uses internally. IPv6 is the newer, longer format built because IPv4 ran out of room for every device on the internet to get its own address. You don’t usually have to choose between them or configure anything.

What each one actually is

IPv4 addresses look like four numbers separated by dots, for example 192.168.1.1. That’s the format behind your router’s default gateway and the one almost every home-network guide uses, because it’s the one people recognize.

IPv6 addresses are longer and written in hexadecimal, separated by colons, something like 2001:0db8:85a3::8a2e:0370:7334. They were designed to fix a specific problem: IPv4 has a fixed, limited address space, and the public internet ran through most of it years ago. IPv6 has enough room that every device could theoretically get its own unique public address instead of sharing one through NAT.

Why your network runs both

This setup is called dual-stack, and it’s the default on basically every router and ISP connection sold today. Your router keeps handing out private IPv4 addresses to devices on your network the same way it always has, using the DHCP pool covered in static IP vs dynamic IP. At the same time, if your ISP supports it, your router also gets an IPv6 allocation and hands pieces of it out to your devices.

A device with both just uses whichever one the thing it’s connecting to actually supports. A site or app that only answers on IPv4 gets reached over IPv4. One that supports IPv6 might get reached that way instead, often slightly more directly since there’s less translation involved. You don’t pick; the device and the remote server sort it out between them.

Where IPv4 still matters more

Inside your own house, IPv4 is still doing the heavy lifting. Your router’s admin page, port forwarding rules, and DHCP reservations are all IPv4-based on nearly every consumer router. If you spot an unfamiliar device on your network and want to identify it, that’s also an IPv4-era workflow, usually starting with a MAC vendor lookup. If you’re logging into your router or setting up anything by address, you’re almost certainly typing an IPv4 one.

IPv6 mostly runs in the background, handling outbound traffic to IPv6-capable destinations without you ever seeing an address or touching a setting.

When a setting is actually worth changing

For most people, never. But there are a few specific cases where it comes up:

A VPN that behaves oddly. Some VPN clients only tunnel IPv4 traffic, which can let IPv6 traffic leak outside the tunnel. If a VPN provider’s support page tells you to disable IPv6, that’s the reason.
A router stuck on an old or buggy IPv6 implementation. Occasionally a specific router model has a flaky IPv6 stack that causes random drops, and the fix really is turning it off until a firmware update resolves it.
Troubleshooting a specific app or game. If something only fails over one protocol, temporarily toggling IPv6 off is a reasonable diagnostic step, not something to leave changed by default.

Outside of a concrete symptom like one of these, there’s no speed or security reason to turn IPv6 off, and no setting to “optimize” day to day.

How to check which one you’re using

If you’re just curious, most routers show both addresses on their status or network-map page, reachable through the same admin login you’d use for anything else. A device’s own network settings will usually list an IPv4 address alongside one or more IPv6 addresses at the same time, which is normal and expected, not a sign anything is misconfigured.