This is a warning about an unresolved issue I discovered when using the TP-Link Archer A6 v3 (and the similar Archer A9 V6) Wi-Fi router in access point mode.
When a Wi-Fi device is connected to the Archer A6 and later roams away to another access point, the roaming device loses connectivity with other devices that are still connected to the Archer A6.
Although TP-Link's technical support was responsive when I emailed them about this issue, they couldn't reproduce it. The best workaround I found was to replace the hardware.
- My router is an Amazon Eero 6, also acting as a Wi-Fi access point.
- My Archer A6 extends the range of my Wi-Fi network by connecting it to the Eero 6 using a long Ethernet cable and enabling access point mode.
- My desktop is always connected to the Archer A6 via Wi-Fi.
- My laptop roams between the Archer A6 and Eero 6 access points via Wi-Fi.
When I move my laptop away from the Eero 6 and closer to the Archer A6, it roams from the former to the latter because of the stronger signal. After this occurs, my laptop can no longer communicate with devices that are still connected to the Archer A6, including my desktop. However, my laptop can still communicate with other network devices, including reaching the internet.
When my laptop pings my desktop, it reports "destination host unreachable". A packet capture on my laptop shows that it is broadcasting ARP requests for my desktop but receives no response. A packet capture on my desktop shows that the ARP requests are received and a response is sent to my laptop (which is never received).
When my desktop pings my laptop, it reports 100% packet loss.
After exactly eight minutes, the problem is resolved and my laptop can communicate with the rest of the network normally.
My guess is that when a wireless device roams away, the Archer A6 neglects to update its bridging table, causing frames destined for the roaming device to continue being sent to its wireless interface, instead of the (now-correct) wired interface connected to the other access point.
- Wait eight minutes after roaming.
- Disable Wi-Fi on the roaming device before moving it near another access point.
- Connect the roaming device to a local VPN, which is not connected to the Archer A6, to proxy traffic to other network devices.
- Replace the Archer A6's OEM firmware with OpenWrt. However, I found that OpenWrt's wireless driver for this hardware was unstable.
- Replace the Archer A6, preferably with hardware from a different manufacturer, since at least one other TP-Link model is also affected.