Watchguard Network Security Practice Test

How can you prevent a network outage when changing the IP address of a Firebox trusted interface?

1. Create a 1-to-1 NAT rule for the subnets

2. Add the old IP address as a secondary address

3. Add the old subnet to the DHCP pool

4. Add a route to the old subnet with the new gateway

The correct answer is: Add the old IP address as a secondary address

Adding the old IP address as a secondary address on the Firebox trusted interface is an effective way to prevent a network outage during an IP address change. By maintaining the old IP address alongside the new one, devices that still utilize the old IP will be able to communicate with the Firebox without interruption. This dual addressing ensures that the transition period allows network devices to update their configurations and move to the new IP address smoothly. During this transition, devices can still reach the Firebox using the old address, which minimizes potential issues that could arise if they were to lose connectivity during the change. Once the network is stable and all devices have recognized the new IP address, the old IP can then be removed from the secondary address list without causing any disruption. Other options, while they might seem plausible, do not effectively address the immediate need for continuity. For instance, creating a NAT rule or modifying the DHCP pool do not provide a direct and immediate way for devices to access the Firebox if they still depend on the old IP address. Similarly, adding a route to the old subnet with a new gateway may complicate the routing process rather than ensuring seamless communication during the transition.