My former modem was replaced by a all-in-one modem/router (10.1.9.1/24) after a speed upgrade. I still have my DD-WRT router (10.1.10.1/24), which I want to be my main router, i. e. as DHCP server, VPN server, static arp cache entries etc.
I figured since I want two different subnets, I should connect the modem/router to the dd-wrt router LAN to WAN.
But the clients connected to the dd-wrt router don't have access to the internet. The router itself gets assigned an IP address on its WAN interface, either a static one or via DHCP.
I think the first problem is a subset of the 2nd.
What I tried so far: I've set up two subnet, as you can see above. The 1st is 10.1.9.1/255.255.255.0, the second 10.1.10.1/255.255.255.0 (also tried 255.255.240.0). IP of first is gateway of 2nd router.
QUESTION What do I have to configure on the dd-wrt router to have its clients reach the internet? And what do I have to do, if I want to reach the outer subnet from the inner one, i. e. reach the webinterface of the new all-in-one device.
Additional info The first device has a very simplistic interface. It's an Ubee EVW3226.