Refer to the exhibit. The FCoE traffic fails to traverse the vfc2 interface. The VSAN 102 is configured for vfc2. Which action resolves the issue?

Question

Exhibits

Options

• AEnable LLDP on the interface vfc2
• BActivate DCBX on the N9K switch
• CActivate DCBX on the interface e101/1/2
• DEnable LLDP on the neighbor switch

• A
  3% (1)
• B
  13% (4)
• C
  6% (2)
• D
  77% (24)

Explanation

DCBX (Data Center Bridging Exchange) is the protocol that negotiates the lossless Ethernet parameters (like Priority Flow Control) that FCoE requires - but DCBX runs on top of LLDP, meaning both ends of the link must have LLDP enabled for the negotiation to complete. If the neighbor switch has LLDP disabled, DCBX cannot exchange DCB parameters, so the vfc2 binding cannot establish a lossless fabric and FCoE traffic fails.

Why the distractors are wrong:

• A - LLDP cannot be enabled on a vfc interface; vfc is a virtual FC interface that binds to a physical Ethernet port - LLDP only operates on physical interfaces.
• B - Nexus 9K switches have DCBX active by default at the global level; re-activating it globally does nothing when the real problem is the neighbor can't respond to DCBX advertisements.
• C - The exhibit implies DCBX is already configured on e101/1/2 (the physical interface bound to vfc2); the local side is fine - the failure is the neighbor's silence due to LLDP being off.

Memory tip: Think of DCBX as a handshake - both hands must be raised. DCBX speaks LLDP, so if the neighbor switch isn't "speaking" LLDP, the handshake never completes and FCoE can't flow. "No LLDP on neighbor = no DCBX = no FCoE."

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