Which statement is correct about per-flow load balancing?

Per-flow load balancing ensures that all packets belonging to the same traffic flow are consistently forwarded out of the same egress interface. The router or switch calculates a hash based on packet header fields (e.g., source/destination IP, port numbers) to determine the egress path. This method maintains packet order for a given flow, which is critical for stateful applications. While it distributes different flows across multiple paths, it keeps individual flows intact on a single path.

A. This describes per-packet load balancing, which can cause out-of-order packet delivery for a single flow.

B. The primary goal of per-flow load balancing is to prevent out-of-order packet delivery, not guarantee it.

D. While this is a desired outcome, the core mechanism is sending packets of the same flow through the same port, making C the more direct answer.

1. Juniper Networks TechLibrary. (2023). Understanding Per-Flow Load Balancing. Junos OS Routing Protocols Configuration Guide. "With per-flow load balancing

all packets for a certain flow are sent to the same next-hop router."

2. Juniper Networks TechLibrary. (2023). Example: Configuring Per-Flow Load Balancing. Junos OS Routing Protocols Configuration Guide. "To configure per-flow load balancing

you include the load-balance per-flow statement... This ensures that for a given flow

packet ordering is maintained..."