When combined with Intel's latest I218-V Ethernet and ROG's GameFirst III software, LANGuard is part of ROG's design leadership in its gamer Ethernet.
You'd think there's not much you can do to a simple RJ45 socket, right? Well it turns out there's plenty of antiquated tech inside, like old, circular filters and wires everywhere; as you can see below, on the left. If anything, LANGuard (on the right) will satisfy your OCD.
ROG engineers modernized the design with advanced signal-coupling technology and premium surface-mount components, which, add protection from power spikes and keep the (Gigabit) Ethernet signal cleaner, reducing the chance of errors. These are normally corrected by error checking mechanisms, but this requires CPU time that could be devoted to your game!
Look for the red LAN port on ROG motherboards and only ROG motherboard - like the Maximus VII Gene below - then you know you've got LANGuard, Intel GigE and GameFirst III!