This is a 64-bit bitmap that rolls up the fault severities reported by every child component under this service profile (adapters, vNICs, boot policy, FSM tasks, etc.) into a single aggregated fault-severity value stored on the service profile itself. A network admin watching this service profile does not need to walk its whole subtree to know something is wrong underneath it; a non-zero fltAggr on this Server row means at least one child object under that specific profile currently has an outstanding fault. For example, fltAggr might read 0 while the profile is healthy, then flip to a nonzero bit pattern the moment a vNIC under that profile loses fabric connectivity, well before the admin drills into the vNIC itself.