How to Get the Most Out of the UniFi Flex XG: Power, Cables, Setup & Pro Tips

Hey folks! Juan David here – Flytec’s Tech Support Lead and your friendly UniFi Certified Trainer. You already know I’m obsessed with the little things that make a huge difference in your network. And today, I want to give you the real hands-on guide to mastering the UniFi USW-Flex-XG.

You got the switch. Now what? Let’s make sure you're squeezing every gigabit out of it.

Step 1: Power It the Right Way

The Flex XG offers two power options:

• PoE+ (802.3at) on the 1GbE port
• USB-C 5V/5A adapter (included in the single-pack)

But listen up:

• That PoE+ port is only 1Gbps for data. You can use it just for power if you're aiming for full 10G uplink.
• If you're uplinking to a 10G switch or router, power the UniFi Flex XG via USB-C or PoE+, but run your uplink through one of the 10G ports.

Juan Tip: On my setup, I feed PoE into the 1G port from a UniFi switch (just for power), disable the data on that port, and uplink via a Cat6a cable to my UDM-SE on a 10G port. Boom. Full speed, single cable.

Step 2: Use the Right Cables (Seriously)

If you’re going 10G, don’t mess around with cheap or old Ethernet cables.

• Use Cat6a or better for anything over 5 meters
• Shielded cables are a good call in noisy environments
• Patch panels and keystones? Make sure they’re 10G-rated too

Real Talk: A lot of "my 10G link drops randomly" issues I see are bad cable quality or improper termination. Don't let an old Cat5e cable ruin your 10G dreams.

Step 3: Assign Its Role Wisely

Here are some proven roles the UniFI Flex XG can take in your network:

✅ Edge Aggregator

Place it near your desk or a cluster of high-speed devices (PCs, NAS, APs), and uplink back to your core. Perfect for home labs and studios.

✅ Media Workflow Booster

Need ultra-fast transfers between your NAS and editing rig? Flex XG gives you near-direct speeds without SFP+ complexity.

✅ Copper Extension to Fiber Core

If you're using a USW-Aggregation switch as your core (SFP+ ports only), plug in a 10G RJ45 SFP+ module and connect it to the Flex XG. Now you’ve got 10G copper ports where you need them.

Step 4: UniFi Controller Magic

Once adopted into your UniFi controller, take full advantage:

• Enable VLANs for segmented networks
• Monitor port stats in real-time
• Use LAG (Link Aggregation) if your NAS or server supports it
• Apply ACLs if you want to restrict traffic

Juan Reminder: It’s Layer 2 only, so routing between VLANs on needs to be done at your gateway (UDM, UDM-SE, etc.). But for Layer 2 switching? It flies.

Troubleshooting Like a Pro

Problem: Port keeps disconnecting at 10G
Fix: Check your cable. Try locking the port to 5G or 2.5G temporarily and upgrade your NIC drivers.

Problem: Device won’t power up over PoE
Fix: Remember, the Flex XG does not provide PoE out. Only PoE in.

Problem: Switch feels hot
Fix: Totally normal. It’s fanless and uses the metal chassis to dissipate heat. Just keep airflow around it.

Final Thoughts

This switch isn’t just a good piece of gear. It’s a secret weapon. With the right setup, the UniFi Flex XG brings data center speeds to your desktop, studio, or small business.

And the best part? It stays silent, stays cool, and just works.

Got questions about your setup? Call us to our UniFi Support Line 855-4-FLYTEC or chat with us at FlytecComputers.com. I’m always happy to help you unlock the full power of your network.