https://community.cisco.com/t5/other-network-architecture/packet-tracer-6-0-1-buffer-full/td-p/2464128
So, the problem is actually not even a problem, rather than a misunderstanding of how the protocol filters work in PacketTracer's simulation mode. If you go back and enable all the protocols to be visible in the workspace by toggling the (show all/None) button in the simulation mode, you'd find a plenty of messages, most of which are STP messages, and you'd discover that your event list has really been saturated.
Toggling the filters doesn't stop the program from capturing the events, and apparently, the events are captured faster, and you can barely use one ICMP message without getting ( Event buffer full ) error.
To workaround that, head to (Options) in the main menu of your program and select (Preferences).
Once the preferences window appears, go to (Miscellaneous) tab and optimize the following options to meet your needs:
Simulation - Buffer full action:
- Prompt: means that the event buffer error message appears.
- Auto clear EventList: means the previous events in the list will be cleared and you continue with the current running ones.
- Auto view previous events: means that you pause the simulation at the current moment.
You should choose the first option if you can't decide, or just leave it because that's the default.
The second option however, is going to solve your problem:
Simulation - Buffer behavior:
- Buffer filtered events only
You must tick this option to activate it if you only care about the filtered types of messages, and the error will eventually disappear.
Only the messages you are interested in, will be captured and saved to the event buffer or list.
I hope this solves the problem for the future.