We are chasing high system utilization rates at our central location. When the CPU rate is low (between 5-15%) there is no TID named USL Task. When CPU runs high (between 94-98%) there is a TID named USL Tack running between 50-80%.
We have found many errors, loops, rogue APs, even a hub! After finding each of these our rmon stats broadcast/multicast numbers dropped and out CPU numbers came down to 5-15%. USL Task would go away. Check an hour later and the USL Task is back, churning up 50-75%, and CPU is hovering in the mid 90s. When it peggs at 100% things get really ugly since this is the main egress from the entire school district.
What is USL Task and what can I learn from it?