There are two USB 2.0 ports on the back of the DFL-CPG310 for connecting a USB printer and sharing it on your network. Once a printer is connected to a USB port, the DFL-CPG310 will detect it and present an additional menu screen to customize the printer as necessary.
The OPT port offers multi-functionality, including the ability to connect a second WAN connection, or to connect and define a DMZ subnet. For second WAN connections, the DFL-CPG310 will failover from the primary WAN connection to a secondary WAN connection for Internet redundancy. In DMZ mode, this port will support a separate LAN subnet, complete with a DHCP server, and allow unrestricted traffic in and out of the interface.
There is also a serial port on the DFL-CPG310, which can be used either for a console connection, or to configure a backup modem. This backup modem connection, configurable for dial-up or ISDN BRI services, can also be set up for WAN failover.
Virtual Private Networking
The DFL-CPG310 is a "Security VPN Firewall" with both Client and Site-to-Site VPN functionality. VPN Client access involves using a software client on a remote PC to set up a secure connection to the home LAN, while Site-to-Site VPN access uses configurations in routers to securely connect LANs. Out of the box, the DFL-CPG310 provides five licenses for the VPN Client software and supports two Site-to-Site VPN tunnels.
The DFL-CPG310 supports DES, 3DES, AES-128 and AES-256 encryption, and both MD5 and SHA1 authentication. Diffie-Hellman Group 1 (768-bit), Group 2 (1024-bit), and Group 5 (1536-bit) Phase 1 and Phase 2 key exchange security are also supported. Perfect Forward Secrecy can be enabled to further enhance key exchange security.
Figure 10 below is a simple diagram depicting a network supporting VPN Client software. A common use for this technology is for mobile employees to securely access the home LAN over the Internet.
Figure 10: A VPN client software diagram
VPN Client access to the D-Link LAN is enabled through the CheckPoint VPN-1 Secure Client software. The software is available both on the included CD and through a simple download, with the download link provided in the DFL-CPG310's VPN Server menu screen, as you can see on the right in Figure 11. This is handy, enabling an administrator to load the VPN client software on each PC without carrying around a CD.
Figure 11: VPN options and a link to download the VPN client software
As we've seen with other VPN Client offerings lately, Vista isn't listed as a supported OS. I installed the software on an XP Pro machine using defaults, simply entering the dynamic DNS name of the D-Link as the target site, as you can see in Figure 12.