In Layer 2 mode with multiple VLANs configured, what parameter is used to enable traffic passage?

In Layer 2 mode with multiple VLANs configured, what parameter is used to enable traffic passage?

• A. The IP address and subnet mask
• B. Layer 2 parameters in addition to the 4-tuple
• C. Only the MAC address
• D. Only VLAN ID

Answer: (B)

In a setup that operates at Layer 2 with multiple VLANs, forwarding decisions rely on the combination of Layer 2 identifiers and higher-layer session information. The VLAN ID tells the device which virtual network the frame belongs to, while the MAC address identifies the specific destination within that VLAN. At the same time, the 4-tuple (source IP, destination IP, source port, destination port) distinguishes the exact communication flow at the higher layers. So, to enable traffic passage in this multi-VLAN Layer 2 environment, you need Layer 2 parameters alongside the 4-tuple. The IP address and subnet mask are Layer 3 details and aren’t used to gate Layer 2 forwarding here, and using only the MAC address or only the VLAN ID would not uniquely identify and permit the correct traffic path when multiple VLANs and multiple sessions are present.

In a setup that operates at Layer 2 with multiple VLANs, forwarding decisions rely on the combination of Layer 2 identifiers and higher-layer session information. The VLAN ID tells the device which virtual network the frame belongs to, while the MAC address identifies the specific destination within that VLAN. At the same time, the 4-tuple (source IP, destination IP, source port, destination port) distinguishes the exact communication flow at the higher layers. So, to enable traffic passage in this multi-VLAN Layer 2 environment, you need Layer 2 parameters alongside the 4-tuple. The IP address and subnet mask are Layer 3 details and aren’t used to gate Layer 2 forwarding here, and using only the MAC address or only the VLAN ID would not uniquely identify and permit the correct traffic path when multiple VLANs and multiple sessions are present.