The HCIE Lab Guide states: “For bond ports of the Bond4 type on the host, the dynamic LACP mode must be configured for the bond ports on the switch.”

Therefore, the correct selection is B. Mode 4.

Mode 4 corresponds to the Bond4/LACP-based link-aggregation design used where multiple physical Ethernet links operate as one logical connection. When front-end switches are deployed as an M-LAG pair, link aggregation can span the two physical switches while presenting a single logical aggregation relationship toward the connected system.

This design is specifically appropriate for switch-port and link redundancy. If one member link or one associated switch-side port fails, the remaining member links continue carrying traffic without requiring the logical storage interface to be taken offline. It also enables bandwidth aggregation under normal conditions.

The Lab Guide ' s networking principles distinguish this from simple standalone interfaces and explicitly require dynamic LACP on the switch side when Bond4 is used. That requirement aligns with an M-LAG front-end design where resilient link aggregation is required across redundant switches.

Study Guide Topics: Data Protection Solution → OceanProtect Network Planning → Front-End Storage Network → Bond4 → Dynamic LACP → M-LAG.