Refer to the exhibit. A Cisco UCS B-Series Blade Server is configured to boot from a shared storage via an iSCSI network. When a service profile is associated with the blade, the blade fails to…

Question

Exhibits

Options

• APlace VLAN 0 on the interface that connects to the storage
• BRegister the blade as an initiator on the storage array
• CImplement a Layer 3 connection between the blade and the storage
• DEstablish a Layer 2 connection between the blade and the storage

• A
  76% (22)
• B
  7% (2)
• C
  14% (4)
• D
  3% (1)

Explanation

Placing VLAN 0 (the native/untagged VLAN) on the interface connecting the blade to the storage resolves the LUN attachment failure because iSCSI boot traffic in a Cisco UCS B-Series environment requires Layer 2 reachability on the correct VLAN. If the storage-facing interface is not configured with the native VLAN, the iSCSI initiator frames are either tagged incorrectly or dropped entirely, preventing the blade from discovering and attaching the LUN during boot.

Why the distractors are wrong:

• B is incorrect because in UCS, the initiator IQN and credentials are defined within the service profile's iSCSI boot policy - manually registering the blade on the storage array is not the missing step here; the network path is the problem.
• C is incorrect because iSCSI boot in UCS B-Series operates over Layer 2 within the fabric; introducing a Layer 3 (routed) hop adds unnecessary complexity and is not the standard or required design.
• D is a near-miss - a Layer 2 connection likely already exists; the specific fix is VLAN configuration on that interface, not establishing a new Layer 2 link from scratch.

Memory tip: When iSCSI LUN attachment fails in a UCS blade environment, think "VLAN before everything" - the iSCSI frames must traverse the fabric untagged (native VLAN 0) to reach storage, so a VLAN mismatch is the most common culprit before you start blaming initiator registration or routing.

No community discussion yet for this question.