My home network setup looks like this:

Both routers are TP-Link TL-WR1043ND routers. The basement router handles all devices in the house that are connected via cable, handing out addresses for the 10.89.49.0/24 network via DHCP. Wireless doesn’t really work from the basement, as the signal is too weak, so I have disabled it.

To do WiFi, I have added a second (identical) router downstairs. On the WAN side it is assigned the 10.89.49.101 IP address from the basement router, and on its LAN it provides the 10.89.7.0/24 network. Basic internet access works flawlessly from any device this way.

I am now facing the problem that I am not able to communicate (e.g. SSH) between all devices, wired or wireless. I am able to connect from a wireless device to a wired device, for example SSH-ing from 10.89.7.X to 10.89.49.Y, but it doesn’t work the other way round—despite the fact that I have added a static route to the basement router:

Does anybody have any idea on how to solve it? Both routers have already been upgraded to use the most recent firmware from TP-Link.com (Build 110429), to no avail.

Errata: I would like to stick with the official firmware, switching to something like DD-WRT or OpenWrt only as a last resort.