Quick Reference Guide
ProSafe VPN Firewall 50 FVS338 Reference Manual
Introduction 1-3
v1.0, January 2010
Security
The VPN firewall is equipped with several features designed to maintain security, as described in
this section.
• PCs Hidden by NAT. NAT opens a temporary path to the Internet for requests originating
from the local network. Requests originating from outside the LAN are discarded, preventing
users outside the LAN from finding and directly accessing the PCs on the LAN.
• Port Forwarding with NAT. Although NAT prevents Internet locations from directly
accessing the PCs on the LAN, the FVS338 allows you to direct incoming traffic to specific
PCs based on the service port number of the incoming request. You can specify forwarding of
single ports or ranges of ports.
• Exposed Host (Software DMZ). Incoming traffic from the Internet is normally discarded by
the FVS338 unless the traffic is a response to one of your local computers or a service for
which you have configured an inbound rule. Instead of discarding this traffic, you can have it
forwarded to one computer on your network.
Autosensing Ethernet Connections with Auto Uplink
With its internal 8-port 10/100 switch, the FVS338 can connect to either a 10 Mbps standard
Ethernet network or a 100 Mbps Fast Ethernet network. Both the LAN and WAN interfaces are
autosensing and capable of full-duplex or half-duplex operation.
The firewall incorporates Auto Uplink
TM
technology. Each Ethernet port will automatically sense
whether the Ethernet cable plugged into the port should have a ‘normal’ connection such as to a
PC or an ‘uplink’ connection such as to a switch or hub. That port will then configure itself to the
correct configuration. This feature also eliminates the need to worry about crossover cables, as
Auto Uplink will accommodate either type of cable to make the right connection.
Extensive Protocol Support
The FVS338 supports the Transmission Control Protocol/Internet Protocol (TCP/IP) and Routing
Information Protocol
(RIP).
• IP Address Sharing by NAT. The VPN firewall allows several networked PCs to share an
Internet account using only a single IP address, which may be statically or dynamically
assigned by your Internet service provider (ISP). This technique, known as NAT, allows the
use of an inexpensive single-user ISP account.