Unifi reduces U6 In-Wall Access Points (U6-IW) speed post sales

Unifi reduces U6 In-Wall Access Points (U6-IW) internal routing capabilities to 300–400 Mbit/s from advertised 1000 Mbit/s post sales via firmware update without disclosing it!

Background

In mid-2022, I purchased three Ubiquiti UniFi U6 In-Wall Access Points (U6-IW) via the European online shop (https://eu.store.ui.com/eu/). These devices are advertised as having four integrated Gigabit Ethernet ports (1 GbE) both in the product description on the Ubiquiti online shop and in the official technical data sheet. In addition to the Wi-Fi function, the devices feature a built-in 4-port GbE switch, via which wired devices can be connected.

In practice, however, these ports only achieve a throughput of approx. 300–400 Mbit/s (approx. 40 MB/s) when forwarding local network traffic via the access point’s uplink to the rest of the network. This corresponds to merely 30–40% of the advertised gigabit performance.

In contrast, the same connection delivers almost full throughput (approx. 110 MB/s or 929 Mbit/s) when traffic flows directly between the internal ports of the U6-IW or when devices are connected directly to the USW 24 PoE switch. Important: No VLANs are used in my network. All devices are located in a single, flat subnet (10.0.0.0/22) without any inter-VLAN routing. All tests described below were carried out in this simple network configuration without VLANs.

[Incident]

All tests were carried out using iperf3 under controlled conditions. The results were submitted in full to Ubiquiti Support (ticket #5394191), which did not dispute them:

Internal switch of the U6-IW (port-to-port): 114 MB/s – full Gigabit speed
Directly on the USW 24 PoE (without U6-IW): 110 MB/s – full Gigabit speed
iperf3 directly against the U6-IW via the uplink: 929 Mbit/s – full speed
Forwarding via the U6-IW uplink to the rest of the network: only approx. 40 MB/s (approx. 320 Mbit/s) – massive loss of throughput
Speedtest.net via the same path: 800+ Mbit/s download – only internet traffic is correctly accelerated

These tests were carried out using various operating systems (Windows and Linux/Gentoo), different network cards, different cables and different ports on the U6-IW. The result was consistently reproducible.

Ubiquiti's response

Following a detailed fault analysis, Ubiquiti Support confirmed the issue as a known hardware limitation. The explanations and proposals from Ubiquiti are set out and assessed below:

Hardware limitation of the CPU

Ubiquiti explained that the U6-IW’s CPU falls back to a slower packet processing method under certain traffic conditions. This affects local traffic that is forwarded via the uplink.

Assessment: This limitation is not mentioned in any of the official documents – neither in the technical data sheet, nor in the online shop’s product description, nor in the firmware documentation. The customer has no way of finding out about this restriction before purchase. All materials refer exclusively to “Gigabit Ethernet” without any restrictions.

Use /24 subnet size

Ubiquiti claimed that the throughput loss occurs with subnets larger than /24. My network uses a /22 subnet (10.0.0.0/22). Ubiquiti recommended switching to /24.

Assessment: This claim is technically unfounded. The U6-IW operates as a Layer 2 switch. A Layer 2 switch forwards packets solely on the basis of MAC addresses and has no knowledge of the subnet mask. The subnet size affects neither the forwarding tables nor the CPU load of a Layer 2 device. A /22 and a /24 subnet differ only in the number of available IP addresses – the switching process is identical. Furthermore, this alleged limitation is not documented anywhere and was only cited as an explanation after weeks of escalation. Ubiquiti itself admitted that the ‘Packet Processing Engine’ handles it this way – which identifies the problem as a firmware bug, not a legitimate limitation.

Firmware downgrade to version 6.6

Ubiquiti suggested downgrading the firmware to version 6.6.77, but at the same time warned that certain traffic might not be forwarded at all in this version. Ubiquiti stated explicitly that the Accelerated Traffic Path still functioned on the older firmware.

Assessment: This statement is revealing in several respects and is supported by an analysis of the publicly available firmware release notes on community.ui.com:

Firstly, Ubiquiti’s own statement confirms that the device was originally capable of delivering the advertised gigabit speed via the uplink. The throughput limitation was therefore introduced retrospectively via a subsequent firmware update – it is thus a regression, not an inherent hardware limitation.

Secondly, the firmware history shows a striking gap: the last firmware for the U6-IW prior to the update was version 6.6.77 from August 2024. It was not until 14 months later, in October 2025, that the U6-IW received its next update with version 6.7.32. During this period, the device’s entire switch port code was fundamentally overhauled. The release notes for versions 6.7.32/6.7.33 introduce, amongst other things, a new ‘Instant Changes – Configuration Engine’, which fundamentally alters packet processing. Furthermore, this version contains an explicit bug fix for the U6-IW: “Fixed communication issues with VLAN networks on U6-IW switch ports”. The immediate successor version, 6.7.35, had to fix another U6-IW-specific switch port bug: “Fixed an issue that caused IPTV to malfunction when the receiver was connected to a U6-IW switch port”. Two consecutive bug fixes to the U6-IW’s switch port code demonstrate that the code in this area is unstable.

Thirdly, numerous users on the official Ubiquiti Community Forum report serious issues with the U6-IW following the update to 6.7.33, including: consistent reboot issues in enterprise environments with 48 U6-IW devices (rolling back to 6.6.77 resolved the issue), failures of wired ports during VLAN traffic, missing MAC/IP addresses for wired devices, and critical kernel crashes in the multicast handler.

Fourthly, a downgrade to 6.6.77, which is known to cause total failures in packet forwarding, is not a reasonable solution. Ubiquiti itself admits that both firmware versions are faulty: the current version limits throughput, whilst the older version blocks traffic completely. The manufacturer has thus degraded the functionality of a product already sold via a software update, without informing the customer or providing a functional alternative.

Change cabling

Ubiquiti recommended rewiring the end devices so that they are not both connected via the same U6-IW.

Assessment: The U6-IW is explicitly marketed as an in-wall access point with an integrated 4-port GbE switch. The purpose of this product is to connect multiple devices via the integrated ports and forward their traffic via the uplink. The recommendation not to do this contradicts the advertised intended use of the product.

10% discount or upgrade to U7-IW

Ubiquiti offered a 10% discount voucher for a future order in the online shop. In addition, the purchase of the successor model, the U7-IW, was recommended.

Assessment: A discount on a new purchase is no substitute for rectifying an existing defect. The customer is expected to purchase a successor product at their own expense to compensate for a manufacturer’s fault. Furthermore, the proposed U7-IW is not an equivalent replacement: the U7-IW has only two LAN ports, whereas the U6-IW has four LAN ports. A functionally equivalent replacement would be the U6-Enterprise-IW, which also has four LAN ports – provided this model does not have the same throughput limitation. This is unacceptable from a consumer protection perspective.

Lawsuit

Complained filed at https://www.evz.de/en/ on April 01. 2026 (Reference ECCDE-105177) - no response until today (May 07. 2026)

Consumer response

https://www.reddit.com/r/UNIFI/comments/1t60biv/unifi_cripples_u6_inwall_access_points_u6iw_post/

https://olausson.de/news/9-news/27-unifi-cripples-u6-in-wall-access-points-u6-iw-post-sales

References