WithLeast Connections (member), BIG-IP attempts to send new connections to the pool member with the fewest current connections. In a perfectly “stateless” scenario (no affinity), this often trends toward a fairly even distribution over time.
However,persistence overrides load balancing:
When apersistence profileis applied, BIG-IP will continue sending a client (or client group) to thesame pool memberbased on the persistence record (cookie / source address / SSL session ID, etc.).
This means even if another pool member has fewer connections, BIG-IP may still select the persisted member to honor session affinity.
The result can beuneven active connection counts, even though the configured load balancing method is Least Connections.
Why the other options are not the best cause:
A. Priority Group Activation is disabledPriority Group Activation only affects selection when priority groups are configured; disabling it does not inherently create uneven distribution under Least Connections.
B. SSL Profile Server is appliedA server-side SSL profile affects encryption to pool members, but it does not by itself cause skewed selection across pool members. (Skew could happen indirectly if members have different performance/latency, but that’s not the primary, expected exam answer.)
D. Incorrect load balancing methodLeast Connections is a valid method and does not itself explain unevenness unless something is overriding it (like persistence) or pool members are not all eligible.
Conclusion:
Apersistence profileis the most common and expected reason that active connections becomeunevenly distributed, because persistencetakes precedence overthe Least Connections load-balancing decision.
