So, what can we not have redundancy in our layer 2 topology? Of course, we can. The only way to bring the switches back to the operation is to break the loop by pulling one of those cables. Even console connection may refuse to accept your commands. An attempt to access them remotely using SSH/telnet will fail. In a few seconds the switches become unresponsive. If you look at switches that experience a broadcast storm, you will notice that all their LEDs are flashing amber like a Christmas tree. It is true that there is not mechanism to stop it, but all three switches in the topology will be so busy sending out this broadcast, that eventually all its resources are consumed and they stop sending anything at all. This broadcast is running in the loop in both directions endlessly. You can write the rest of the story on your own. Then, a tad later it receives this same broadcast frame from SW1 and again it floods it out all active ports except the port it arrived on. SW3 receives the broadcast frame on its F0/12 port and floods it. SW1 receives it on port F0/13 and floods it out of other ports. SW2 upon receiving it, floods it out all its active ports. In this scenario, PC1 sends a broadcast frame. Previous mapping is removed and F0/14 becomes the outbound port for 0000.1111.1111 now. This causes a little confusion as SW3 learned it earlier on and it was port F0/12 before.
PACKET TRACER LABS FOR STP BROADCAST STORM MAC
SW3, upon receiving the frame on its F0/14 port, reads the source MAC address (0000.1111.1111) and maps it to port F0/14 this time.
![packet tracer labs for stp broadcast storm packet tracer labs for stp broadcast storm](https://itexamanswers.net/wp-content/uploads/2019/05/2019-05-21_151831.png)
This way, the frame is sent out SW1's port F0/14 towards SW3. Since SW1 does not know where PC3 is connected (at least right now) it will flood this frame out all active ports. It learns the source MAC address and maps it to its F0/12 port where it arrived. Now, SW3 receives this frame sourced with 0000.1111.1111 MAC address ( PC1). SW2 floods the frame out F0/12 and F0/13 ports. In our scenario, PC1 sends the frame to PC3 (destination MAC: 0000.3333.3333). This means they have not learned its MAC address yet. Again, let us assume that none of the switches in the picture knows where PC3 is connected.