source: DLINK DIR615 manual
(link for the manual: http://www.dlink.com/products/?tab=3&pid=DIR-615&rev=DIR-615 )
If you are connecting the D-Link router to another router to use as a wireless access point and/or as a switch, you will have to do the following before connecting the router to your network:
• Disable UPnP™
• Disable DHCP
• 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.
To connect to another router, please follow the steps below:
1. Plug the power into the router. Connect one of your computers to the router (LAN port) using an Ethernet cable. Make sure your IP address on the computer is 192.168.0.xxx (where xxx is between 2 and 254). Please see the Networking Basics section for more information. If you need to change the settings, write down your existing settings before making any changes. In most cases, your computer should be set to receive an IP address automatically in which case you will not have to do anything to your computer.
2. Open a web browser and enter http://192.168.0.1 and press Enter. When the login window appears, set the user name to Admin and leave the password box empty. Click Log In to continue.
3. Click on Advanced and then click Advanced Network. Uncheck the Enable UPnP checkbox. Click Save Settings to continue.
4. Click Setup and then click Network Settings. Uncheck the Enable DHCP Server server checkbox. Click Save Settings to continue.
5. Under Router Settings, enter an available IP address and the subnet mask of your network. Click Save Settings to save your settings. Use this new IP address to access the configuration utility of the router in the future. Close the browser and change your computer’s IP settings back to the original values as in Step 1.
6. Disconnect the Ethernet cable from the router and reconnect your computer to your network.
7. Connect an Ethernet cable in one of the LAN ports of the router and connect it to your other router. Do not plug anything into the Internet port of the D-Link router.
8. You may now use the other 3 LAN ports to connect other Ethernet devices and computers. To configure your wireless network, open a web browser and enter the IP address you assigned to the router. Refer to the Configuration and Wireless Security sections for more information on setting up your wireless network.
Features of the DLINK-615 wireless N router
Faster Wireless Networking – The DIR-615 provides up to 300Mbps* wireless connection with other 802.11n wireless clients. This capability allows users to participate in real-time activities online, such as video streaming, online gaming, and real-time audio.
• Compatible with 802.11g Devices – The DIR-615 is still fully compatible with the IEEE 802.11g standard, so it can connect with existing 802.11g PCI, USB and Cardbus adapters.
• Advanced Firewall Features – The Web-based user interface displays a number of advanced network management features including:
• Content Filtering – Easily applied content filtering based on MAC Address, URL, and/or Domain Name.
• Filter Scheduling – These filters can be scheduled to be active on certain days or for a duration of hours or minutes.
• Secure Multiple/Concurrent Sessions – The DIR-615 can pass through VPN sessions. It supports multiple and concurrent IPSec and PPTP sessions, so users behind the DIR-615 can securely access corporate networks.