To address saturation on the data interface of an SDX, which action is appropriate?

• A. Add a second interface to each VPX instance
• B. Configure a failover interface set on each VPX instance
• C. Configure LACP on the SDX for the data interface
• D. Configure LACP on the SDX for the management interface

Answer: (C)

When data traffic is hitting saturation on an SDX, the best way to boost effective bandwidth is to combine multiple physical data links into a single logical link. Configuring LACP on the SDX for the data interface creates a port-channel that aggregates several ports, allowing traffic to be distributed across them and increasing total throughput while also providing redundancy. This directly addresses the bottleneck on the data path by making use of multiple cables/ports packed into one scalable link.

Adding a second interface alone won’t automatically share load unless it is part of a link-aggregation group, and a failover interface set is for high availability rather than increasing sustained throughput. LACP on the management interface doesn’t affect data traffic, since management and data paths are separate. So, enabling LACP on the data interface aligns with the goal of alleviating data-path saturation.