TomatoUSB

Got a tomato Belkin N300 router (toastman build) that is in wireless client mode to connect to another AP, with static LAN ip 12.12.12.1 (gateway mode).

Connect to this router is another Belkin N300 router (same model, same toastman build) which static LAN ip is 12.12.12.2 and that offer internet to all clients on my LAN.

Being a client, I can have internet access and connect to the router's gui using 12.12.12.2, and connect to the other AP using it's ip address.

However, I cannot ping or access the gui of the router in wireless client mode using 12.12.12.1 through the 12.12.12.2 router. I got to directly connect using a cable on that router and then I can access the gui using 12.12.12.1

I don't understand why, and how I should route this… I'd also wish to share a device connected to its USB port, which shouldn't be visible to the primary AP's network, so I'd also need to route this.

I also don't want all my LAN clients to be visible to the primary AP, so I don't want to put the router in wireless client bridge mode (and that all why i have a second router 12.12.12.2 !!! I used to use the brilliant DDWRT repeater mode !!)

Can someone help me ?

primary AP <- wireless -> 12.12.12.1 <- wired -> 12.12.12.2 <-> wired or wireless clients
+internet link

If you use the WAN port on 12.12.12.2 to plug in to a LAN port on the 12.2.2.1 router, your .2 router will automatically block any incoming traffic as it treats it as coming from the internet, in that case you would have to allow remote management in the GUI of tomato.

If I understood correctly and that's what you're doing, another thing to keep in mind is that the LAN portion of your .2 router can't be 12.12.12.0 or your routing won't work properly (WAN and LAN subnets have to be different).

Hope that helps.