Client Mode routing problem

My old WRT54G routers worked for years as an Access Point - Client combo with DD-WRT, but are outdated by now. I want to replace them with a WRT1200AC and WRT1900AC running OpenWRT. The Access Point works as expected and even works with the old Client Mode WRT54G.
The new WRT1900AC Client appears to connect properly with the Access Point, DHCP works for its wlan interfaces, but not for connected computers. So switching off local DHCP for the LAN, as described, makes the router inaccessible. Keeping it on makes the router accessible, but still no connection to the Access Point. The Client router has a static IP-address and the Access point as gateway.
The Network > Diagnostics ping doesn't work either way with IP-addresses.

The description I followed is here:
OpenWrt 19.07.2 r10947-65030d81f3 / LuCI openwrt-19.07 branch git-20.057.55219-13dd17f

Greetings & thank you for reading,

Fred Jan

@fjkraan, welcome to the community!

Ensure that both networks are not identically numbered (i.e. If so, one subnet has to be changed (e.g. renumber the OpenWrt LAN to

Hi lleachii,

Thanks for your response. The two networks are differently numbered, but it might be I don't properly understand how it should be done. I tried to copy the Client mode that worked for the old DD-WRT routers, and OpenWRT works with an other configuration. This is how I wanted it to work (pardon my ASCII-art):

Wired Remote network
 192.168.2.x                                         Wired Local network with internet access                                 
       L ===+                        (static)       +=== W (192.168.1.x)
            |            *1  |
       L ===+            |    wifi *2        |      +=== L
            |=== WRT1900AC --------- WRT1200AC =====|
       L ===+    |                   |              +=== L
            |    |
       L ===+     (static)            (static)

The WRT1200AC is a standard Access Point which connects 192.168.2.x clients to the 192.168.1.x network (NAT). Both its addresses are static. The W(AN) (Internet) port is, the LAN ports and Wifi are Both wifi-bands are enabled (*2).

The WRT1900AC is connected via wifi, both 2.4 and 5 GHz. Both show up in the Active DHCP Lease list and as Associated Stations. From this I assume there is a working connection on wireless level. Note each wireless network (*1) has its own distinct IP-address (192,168.2.x) but different from the LAN. The LAN address is where the OpenWRT local website is.

My assumption is that the wired remote machines should get their IP-address from the local WRT1200AC. At least that is how the DD-WRT Client mode works (it still does and will until I replace the remote WRT54 with the WRT1900AC).

A first question should be whether OpenWRT uses this Client Mode configuration or a different one.

Greetings & thanks for any input,

Fred Jan

A little bit of progress is made. The DD-WRT documentation ( states that only one wifi band should be enabled in Client mode.

PCs connected to the remote WRT199AC have a registered IP-address in the local WRT1200AC, but it does not reach the PC itself. Could it be firewall-related? The DHCP-related packages are flowing in a reverse direction through the Client Mode router.

Greetings & thanks for any input,

Fred Jan