NETGEAR UTM5EW-100NAS Appliance Reference Manual page 444

ProSecure Unified Threat Management (UTM) Appliance Reference Manual
The purpose of the FQDN is to toggle the domain name of the gateway between the IP addresses
of the active WAN port that is, WAN1 and WAN2) so that the remote PC client can determine the
gateway IP address to establish or re-establish a VPN tunnel.
VPN Telecommuter: Dual Gateway WAN Ports for Load Balancing
In a dual-WAN port load balancing gateway configuration, the remote PC client initiates the VPN
tunnel with the appropriate gateway WAN port (that is, port WAN1 or WAN2 as necessary to
balance the loads of the two gateway WAN ports) because the IP address of the remote NAT router
is not known in advance. The selected gateway WAN port must act as the responder.
Figure B-20
The IP addresses of the gateway WAN ports can be either fixed or dynamic. If an IP address is
dynamic, you must use a FQDN. If an IP address is fixed, an FQDN is optional.
B-18 Network Planning for Dual WAN Ports (Dual-WAN Port Models Only)
v1.0, January 2010