A network engineer is configuring a Cisco MDS switch for FCoE. Which two conditions must be considered during the implementation phase? (Choose two.)

Question

Options

• AOn Cisco MDS switches, system-defined class maps for class-FCoE and class-default are
• BThe QoS policy must be identical to other Cisco FCoE switches in the network.
• COn the Cisco MDS, the MTU is set equal to 2112.
• DVLAN 1 or the native VLAN can be mapped to an FCoE VSAN.
• EFCoE is already enabled on a Cisco MDS switch.

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

Explanation

B is correct because FCoE requires lossless Ethernet enforced via QoS (Priority Flow Control/PFC and DCBX), and that policy must be consistent across all FCoE switches in the fabric - a mismatch causes FCoE frames to be dropped, breaking the lossless transport guarantee. E is correct because unlike Cisco Nexus switches (where you must run feature fcoe), FCoE is already enabled by default on Cisco MDS switches, so the engineer does not need to explicitly activate it - failing to account for this distinction can lead to configuration errors.

A is a distractor referencing system-defined class maps (class-fcoe, class-default) that apply to Nexus switches, not MDS. C is wrong because 2112 bytes is the maximum FC payload size, not the Ethernet MTU - FCoE requires an MTU of at least 2158 bytes (FC frame + FCoE encapsulation overhead), and Cisco typically recommends jumbo frames (9216). D is wrong because Cisco explicitly prohibits mapping FCoE to VLAN 1 or any native VLAN; a dedicated, non-native VLAN must be used for FCoE.

Memory tip: Think "BE careful with MDS FCoE" - Both sides must match on QoS, and Expect it already on. The two traps engineers fall into are forgetting QoS consistency and trying to manually enable something that's already there.

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