My home LAN is a rather standard 192.168.2.0/24 network with gateway on 192.168.2.1 and has DHCP on addresses from 100+ configured on an ASUS router (RT-AC66U). The WAN is configured via DHCP from ISP.
My goal is to access a machine at 172.16.5.31 on a 172.16.5.0/24 network, from any machine on my home LAN. I have physical access to the switch to which the machine is connected, but not to the router of that network.
To make a first step toward that goal, I took another router (dd-wrt) and configured a WAN network as 172.16.5.0/24 with WAN IP 172.16.5.37, and configured the LAN side as 192.168.2.0/24 with 192.168.2.98 IP. NAT is activated. No DHCP. No Gateway defined on either WAN or LAN. The WAN port is plugged into the switch residing on 172.16.5.0/24.
Setting up the network manually on a laptop with IP 192.168.2.67 and gateway 192.168.2.98, going exclusively through that dd-wrt works very well. But I want to use that dd-wrt to access the other network as a component in my home LAN. So I connected the LAN sides of the two routers together, and created a static route on my ASUS router like so: Host IP: 172.16.5.31 , Netmask 255.255.255.0 , Gateway 192.168.2.98 (dd-wrt LAN IP), Interface LAN. But I then get an unreachable host error with that configuration.
My idea was to have a device making a request to 172.16.5.31 with packets going to the usual home LAN router which would redirect to the dd-wrt router (static route), which would then do NAT, and route the reply packets back to the device. However this is not working and I am wondering what I am doing/assuming wrong.