If you are connecting the D-Link router to another router to use as a wireless access point, you will have to do the following before connecting the router to your network. First, you need to disable UPnP and DHCP option. Then you need to change the LAN IP address to an available address on your network. The LAN ports on the router cannot accept a DHCP address from your other router. What is the hardware revision and firmware version of your router? You can find this by looking at the bottom of the router, and checking the H/W ver: and F/W ver: section of the sticker located there.