@jakobp Is there a chance you could get a packet capture using the router that works, so we can see any difference in the DHCP/ARP conversations

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.