Quick Reference Guide

ProSafe VPN Firewall 200 FVX538 Reference Manual

B-10 Network Planning for Dual WAN Ports

v1.0, January 2010

For the single gateway WAN port case, the mechanism is to use a fully-qualified domain name

(FQDN) when the IP address is dynamic and to use either an FQDN or the IP address itself when

the IP address is fixed. The situation is different when dual gateway WAN ports are used in a

rollover-based system.

• Rollover Case for Dual Gateway WAN Ports

Rollover for the dual gateway WAN port case is different from the single gateway WAN port

case when specifying the IP address of the VPN tunnel end point. Only one WAN port is active

at a time and when it rolls over, the IP address of the active WAN port always changes. Hence,

the use of a fully-qualified domain name is always required, even when the IP address of each

WAN port is fixed.

• Load Balancing Case for Dual Gateway WAN Ports

VPN Telecommuter

(client-to-gateway through

a NAT router)

Fixed Allowed

(FQDN optional)

FQDN required Allowed

(FQDN optional)

Dynamic FQDN required FQDN required FQDN required

a. All tunnels must be re-established after a rollover using the new WAN IP address.

Note: Once the gateway router WAN port rolls over, the VPN tunnel collapses and

must be re-established using the new WAN IP address.

Figure B-7

Table B-2. IP Addressing Requirements for VPNs in Dual WAN Port Systems

Configuration and WAN IP address

Single WAN Port

(reference case)

Dual WAN Port Cases

Rollover

Load Balancing