It does look like something not quite right. Strange that everything else seems to work ok apart from the ER605 ? TBH I've not much experience of ISPs using DHCP , mine uses PPPoE. I've dropped you a...

@jakobp Looks like your ISP might be insisting on the connection being from a 'fixed' MAC address. Try using the MAC address clone function on the ER605 ( manual page 33 ) to set the same MAC address...

@handycapp The use case is for 2 pc's from 1 subnet to connect to 1 pc on the other subnet via Windows 11P shared folders accessing files in both directions. Any pc from the 50.x subnet still can't...

@handycapp Providing NAT is enabled on router 2 it should just work! Any traffic from the 192.168.100.1 subnet going out of router 2 will be NATed and thus appear to be coming from 192.168.50.200...

@EY8888 Did you try setting the detection zone ? Mine has been recording fine since I did that.

@jlkweb12 Unless you can get the two different computers to use different MAC addresses when in the docking statiom then they will both always be assigned the same IP address by the router via DHCP ....