UniFi Switch 24 PoE

Ubiquiti · rack switch, 1U · USW-24-PoE

what it is

A managed switch for a 19-inch rack, 1U high: twenty-four gigabit ports and two SFP fiber transceiver slots. Steel chassis, 442 × 200 × 44 mm, weight 3 kg — shallow, fits in wall-mount racks. A 1.3-inch touchscreen on the front panel. Passive cooling, no fan.

Sixteen of the twenty-four ports deliver PoE, in the PoE+ standard, up to 32 W per port. And here is something that has to be calculated before purchase:

The difference is more than fivefold — larger than on the forty-eight-port model of the same family. In practice: three PoE+ access points exhaust the budget, while twelve free powered ports remain. A fourth access point will not come up, and it will look like its own failure, not a lack of power.

what we read from it

The state of each of the twenty-six ports separately, and for the sixteen powered ones also the draw.

• PoE draw per port and the total for the device. With a 95 W budget this is not a curiosity, but the number that decides whether the next device will start at all.
• Negotiated speed separately from what the port is capable of — two different numbers, not one that blurs the difference between "slow" and "this is what we get".
• Bad frame, discard and link-down counters on every port.
• Spanning tree changes — on an access switch, usually the first sign of a loop plugged by someone into a free port.
• The number of hardware addresses visible on a port and what is visible on the other end of the cable.
• Power mode and the class of power drawn on every powered port.
• Assignment of ports to VLANs and the link quality rating issued by the device itself.

port layout

The twenty-four copper ports are arranged in two rows of twelve, divided into two blocks of six columns. Numbering runs down, then to the right: 1, 3, 5… on top and 2, 4, 6… on the bottom.

The division visible on the chassis is NOT the power division — and this is the most important thing here. The gap between the blocks runs between port 12 and 13, and the power boundary between 16 and 17. Anyone planning connections by looking at the frame will be off by two columns: ports 13–16 look like they belong to the "right, unpowered" group, but they do have power.

This is the opposite of the sister sixteen-port model, where the line on the panel matches the power boundary port for port.

The two SFP slots are stacked at the right edge: the upper one is port 25, the lower one 26. The touchscreen is at the left edge, the reset hole at the right. On the rear panel there is only the power socket — no fans and no console port.

what to watch out for

• There is no cable test. In the UniFi Network 10.6.106 controller this function does not exist at all.

what we cannot read

• Power on ports 17–24 — they do not have it. This is a hardware limit.
• Internal temperature — the model has no sensor, so a missing value is not a reading failure. With passive cooling and a rack without airflow, it is worth keeping this in mind.
• The actual power ceiling at a given moment — the total draw and the datasheet budget are known, but not how much the switch is ready to deliver under current conditions.

full list of parameters read via SNMP

These are objects the device itself returns over SNMP (names from MIB files). There are no values here, and no port numbers either.

111 parameters

SNMP list source: reading of 1 unit (as of 2026-10-18).