Where is the loadbalancing mode specified.

The load balancing mode is configured inside the pool definition because it controls how the BIG-IP distributes new connections among the pool's members. Defining it at the pool level means each pool can independently use a distinct load balancing algorithm without affecting virtual server or node configuration.

Node definitions hold properties such as connection limits, ratios, and health monitors, but do not include a load balancing mode setting.

The virtual server definition references a default pool but does not itself define the algorithm used to distribute traffic among pool members.

Pool member definitions can override per-member properties like ratio and priority, but the load balancing mode is a pool-level attribute and is not set on individual pool members.