When there are more than 1000 VLANs and more than 70 ports participating in STP, the number of messages exchanged between STP/FDB/HAL modules can consume a lot of system memory when trying to flush the FDB during a STP topology change. To help avoid this high consumption, you can set the flush type from the default of vlan-and-port to port-based.
To set the flush type, enter the command:
configure stpd flush-method [vlan-and-port | port-only]