Handling 802.11 Traffic in a Fabric-Enabled SSID

B.

In a fabric-enabled SSID (Service Set Identifier), the wireless traffic is handled differently compared to a traditional SSID. In a traditional SSID, the wireless traffic is typically bridged locally at the Access Point (AP) and then forwarded to the distribution or core layer of the network.

However, in a fabric-enabled SSID, the wireless traffic is centrally switched back to the Wireless LAN Controller (WLC) for processing. The WLC acts as the central point for the management and control of the wireless network, and it provides a more efficient way to handle the wireless traffic.

Regarding how the 802.11 traffic is handled in a fabric-enabled SSID, there are two parts to the answer:

1. Conversion of 802.11 frames to Ethernet frames: The AP converts the 802.11 frames received from the wireless clients into Ethernet frames, which can be transported over the wired network. This conversion is necessary because most of the network infrastructure is designed to handle Ethernet frames, not 802.11 frames.

2. Encapsulation of Ethernet frames into VXLAN or VLAN: After the conversion of 802.11 frames to Ethernet frames, the traffic is encapsulated either into VXLAN (Virtual Extensible LAN) or VLAN (Virtual Local Area Network), depending on the design of the fabric-enabled network.

Option A states that the user traffic is mapped to a VXLAN on the WLC. This means that the encapsulation used for the fabric-enabled network is VXLAN. VXLAN is an encapsulation protocol that provides a way to extend Layer 2 segments over an IP network. The VXLAN header is added to the Ethernet frame, and this allows the traffic to be transported over the network using a VXLAN tunnel. The VXLAN header contains information about the VXLAN tunnel, such as the VNI (Virtual Network Identifier), which is used to differentiate between different virtual networks.

Option B states that the traffic is encapsulated into VXLAN as well, but the Ethernet frames are first encapsulated into 802.3 frames. This is incorrect, as the AP converts the 802.11 frames into Ethernet frames, not 802.3 frames.

Option C states that the user traffic is mapped to a VLAN on the WLC. This means that the encapsulation used for the fabric-enabled network is VLAN. VLAN is a way to segment a network into multiple logical networks, where each VLAN has its own broadcast domain. The VLAN ID is added to the Ethernet frame, and this allows the traffic to be transported over the network using a VLAN tag.

Option D states that the traffic is encapsulated into a VLAN. This is partially correct, as the traffic is encapsulated into a VLAN tag, but it does not mention that the encapsulation used for the fabric-enabled network can also be VXLAN.

In summary, the correct answer is A, where the user traffic is mapped to a VXLAN on the WLC after the AP converts the 802.11 frames to Ethernet frames. VXLAN is a popular encapsulation protocol used in fabric-enabled networks, and it provides a way to extend Layer 2 segments over an IP network.