Reference Manual for the ProSafe VPN Firewall 25 with 4 Gigabit LAN and Dual WAN Ports
3-4 Network Planning
202-10085-01, March 2005
Inbound Traffic: Dual WAN Ports for Improved Reliability
In the dual WAN port case with rollover (Figure 3-4), the WAN’s IP address will always change at
rollover. A fully-qualified domain name must be used that toggles between the IP addresses of the
WAN ports (i.e., WAN1 or WAN2).
Figure 3-4: Inbound traffi c to dual WAN ports, before and after rollover
Inbound Traffic: Dual WAN Ports for Load Balancing
In the dual WAN port case for load balancing (Figure 3-5), the Internet address of each WAN port
is either fixed if the IP address is fixed or a fully-qualified domain name if the IP address is
dynamic.
Figure 3-5: Inbound traffic to dual WAN ports for load balancing
Note: Load balancing is implemented for outgoing traffic and not for incoming traffic.
Consider making one of the WAN port Internet addresses public and keeping the other
one private in order to maintain better control of WAN port traffic.
Router
netgear.dyndns.org
WAN1 IP
Dual WAN Ports (Before Rollover)
WAN2 IP (N/A)
WAN2 port inactive
Router
WAN1 port inactive
WAN1 IP (N/A)
Dual WAN Ports (After Rollover)
WAN2 IP
netgear.dyndns.org
IP address of active WAN port changes after a rollover (use of fully-qualified domain names always required)
XX
XX
Router
netgear1.dyndns.org
WAN1 IP
Dual WAN Ports (Load Balancing)
WAN2 IP
netgear2.dyndns.org
IP addresses of WAN ports:
use of fully-qualified domain names
required for dynamic IP addresses
and optional for fixed IP addresses