This Hidden Router Setting Might Help Your Older Devices, But There's A Catch

If you've heard of IPv6, it's likely in the context that it's the future of the internet. It's the latest Internet Protocol, the system by which connected devices on the internet identify themselves and find one another. Replacing the long-standing IPv4, the new protocol offers a number of advantages, including a massive increase in the potential number of simultaneously connected devices (79 octillion times more IP addresses than IPv4). IPv6 also opens up easier access to new security features and routes internet traffic more efficiently than IPv4.

However, IPv6 adoption has been slow, and many older devices aren't compatible with it, leading to issues ranging from poor or slow performance to a total failure to update or function. Disabling IPv6 may resolve some of these issues, but may introduce new problems, like decreased compatibility and performance in Google or Comcast services, and bugs when using IPv6-only networks (such as T-Mobile's).

The aforementioned slow adoption of IPv6 has other consequences, as well. Even some of the best VPN services don't fully support IPv6, in which case some of your data may leak through the secure tunnel they create to connect to the internet. Also, because IPv6 can create a unique identifier for every device, it can create more vectors to attack your system.

If you're regularly using older devices that don't fully support IPv6, turning it off may increase performance on those devices. For instance, some users on Reddit report that disabling IPv6 on their routers improved download speeds on Xbox One consoles. BGR's own Adam De'Seta had issues connecting Chromecasts and updating drivers on older laptops using IPv6, and wasn't able to get a new Ecovacs robot to work at all until he shut down IPv6. If you're using an older device that's not hitting the bandwidth or transfer speeds you expect, or is struggling to connect to the internet at all, IPv6 may be the culprit.

One of the main reasons security-minded individuals might want to disable IPv6 is the possibility of IPv6 leaks. If your VPN provider does not properly encrypt or route IPv6 traffic, your operating system or browser may still send IPv6 traffic outside of the secure VPN tunnel. This is common on dual-stack networks, which attempt to connect via IPv6 first and only fall back to IPv4 if IPv6 isn't available. There are also some browsers, like Chrome or Firefox, which use a technique dubbed Happy Eyeballs or Fast Fallback, which attempts to connect by both IPv4 and IPv6 and uses whichever is faster.

While it's possible that disabling IPv6 may make your connection more secure in the specific examples cited above (VPN leaks and creating a larger attack surface for your system), it comes with risks. IPv6 is generally more efficient at routing internet traffic than its predecessor, so it's possible that devices that do support it may slow down. This includes slower or failed connections for some sites, apps, or streaming platforms that have already migrated fully to the newer protocol.

Also, because IPv6 was designed with IPsec integrated into the protocol suite, end‑to‑end encryption, authentication, and data‑integrity checks are part of the standard, rather than requiring additional software. The sheer size of an IPv6 space is also a security asset. It makes it practically impossible for an attacker to scan entire subnets looking for live hosts, unlike IPv4, where such scanning was simpler and cheaper. This lends IPv6 an incidental level of security through obscurity.

IPv6 also includes mechanisms like Secure Neighbor Discovery (SEND) and Cryptographically Generated Addresses (CGAs), which bind a public key to an IPv6 address. This allows devices to cryptographically verify each other's identity and makes it harder for rogue devices to hijack local network traffic. If your VPN is properly configured, leaving IPv6 is often safer (and more future-proofed) than disabling it, though in either instance, installing some basic additional security is highly recommended.