Load balancing on a Junos device involves distributing packets to achieve efficient network traffic management. It primarily balances packets on a per-flow basis to maintain session integrity by ensuring that all packets of the same flow take the same path. Additionally, it is enabled through a policy, requiring explicit configuration to define how the traffic should be balanced. This approach is crucial for both performance and reliability, ensuring balanced resource utilization and consistent delivery of network services.
Unified ISSU is based on nonstop-routing (NSR) and graceful Routing Engine switchover (GRES), and permits software upgrades only. This statement is accurate as it clearly outlines the basis of the Unified ISSU and correctly states its limitation to software upgrades, ensuring minimal disruption.