The flowlimit will not work at the port level without it being globally enabled.
The following are the implementation steps for configuring Flow Setup Throttling.
Notice that the step "Enable FST on the device" is not optional.
Implementing Flow Setup Throttling
To configure FST for a given port classification:
1. Determine an appropriate flow baseline from which flow limits can be set for each port classification type by monitoring the ports associated with each port classification.
a. Set the low- and high-limit actions to be taken for the specified port classification.
2. Set the ports that will use the configured port classification.
3. Enable FST on all ports configured for flowlimiting.
4. Optionally, enable the sending of SNMP traps action globally on the device.
5. Optionally stop creating (drop) new flows
6. Optionally, enable the disable port action globally on the device.
7. Enable FST on the device
8. Verify the configuration or monitor baseline configurations using the FST show commands.