its supposed to that when configured but not block all logs are you surer on that , I just ran it on one of my switches it took fine as below and is working
when its enabled you get a separate section highlighted in logs where you can see how many of the discriminator messages its blocking
(config)#logging buffered discriminator %STORM_CONTROL-3-FILTERED 10000
Specified MD by the name %STORM_C is not found.
(config)#^Z
#sh logg
Syslog logging: enabled (0 messages dropped, 0 messages rate-limited, 0 flushes, 0 overruns, xml disabled, filtering disabled)
No Active Message Discriminator.
No Inactive Message Discriminator.
Console logging: level debugging, 406 messages logged, xml disabled,
filtering disabled
Monitor logging: level debugging, 0 messages logged, xml disabled,
filtering disabled
Buffer logging: level debugging, 406 messages logged, xml disabled,
filtering disabled
Exception Logging: size (4096 bytes)
Count and timestamp logging messages: disabled
File logging: disabled
Persistent logging: disabled
No active filter modules.
Trap logging: level informational, 410 message lines logged
Logging to x.x.x.x (udp port 514, audit disabled,
authentication disabled, encryption disabled, link up),
410 message lines logged,
0 message lines rate-limited,
0 message lines dropped-by-MD,
xml disabled, sequence number disabled
filtering disabled
