I have one network 192.168.0.x which is slowly running out of IP addresses. I wanted to remedy this by creating a second network for mobile devices (192.168.1.x).
The first network has a gateway of 192.168.0.1 and a subnet of 255.255.255.0.
When I got to configure the second network (using an Apple Airport) I set its IP address to 192.168.0.3, its subnet to 255.255.255.0 and its router and DNS to 192.168.0.1. I also activated the DHCP-service for the range of 192.168.1.2 - 200.
This seems to work fine, even though the I received a message that there was a "Double NAT" in the network. Furthermore it tells me "This AirPort base station has a private IP address on its Ethernet WAN port. It is connected to a device or network that is using Network Address Translation to provide private IP addresses. Change your AirPort base station from using DHCP and NAT to bridge mode."
But if I do this, it does not serve the purpose of the AirPort being a separate DHCP for the second address-range (192.168.1.x). Can I just ignore this error, or am I doing something wrong?
I also have noticed that if I now try to change anything about the DHCP or NAT setup on the AirPort I get the error message: "The DHCP range you have entered conflicts with the WAN IP address of your base station". It suggests for me to use 192.168.0.2-200 as DHCP range, but that is not what I wanted. This kind of gives me the feeling that I might not have this set up correctly, even though it works - as I mentioned.