Switch Learning Vs. Switch Forwarding Question
For #CCENT and #CCNA, you need to know how switches learn, plus you need to know how switches forward frames. Sometimes, combining the two concepts (learning and forwarding) for the first time causes some mental hurdles.
In today’s post, we’ll use one of the questions from my ICND1 Cert Guide as a backdrop to work through these same concepts. The question weaves together learning and forwarding. Today’s post poses the question, while the next post works through the logic.
Figure 1: Diagram Used with this Question
The switch begins with no dynamically learned MAC addresses. The PC1 creates and sends a frame with a destination address of 2222.2222.2222. Then PC3 creates and sends a frame destined for PC2’s MAC address of 2222.2222.2222. Which of the following are true about this second frame? (Select all answers that are correct.)
The Possible Answers
A. The switch discards (filters) the frame.
B. The switch forwards the frame out of interface Fa0/1
C. The switch forwards the frame out of interface Fa0/2
D. The switch forwards the frame out of interface Fa0/3