Which of the following is NOT a valid VLAN configuration on the Firebox?

The statement that indicates the correct understanding of VLAN configurations on a Firebox is that an interface can indeed send and receive untagged traffic for one VLAN and tagged traffic for a different VLAN. In VLAN configurations, an interface can be configured in such a way that it supports both types of traffic, allowing greater flexibility in how data is managed within different VLANs.

When managing VLANs, interfaces are often configured to handle specific types of traffic based on tagging. For instance, untagged traffic can be associated with a default VLAN, while tagged traffic can identify packets belonging to different VLANs. This capability allows for streamlined communication and organization within the network.

On the other hand, while it is permissible for two interfaces to send and receive tagged traffic for a single VLAN, and while an interface can manage untagged traffic for a specific VLAN, tagging a VLAN within a mobile VPN virtual pool is not standard practice for VLAN declarations in Firebox. Since options concerning configurations that do not align with standard practices tend to be incorrect, it validates the integrity of VLAN setups.

Understanding these VLAN configurations and their impacts on the overall network structure ensures proper management and performance of a Firebox device.