This post is from our Cisco CCNA Training Course. Instructor Mark Jacob was presenting a Q&A Session in our ICND1 CCNA class and answered a question regarding MAC Addresses and when they get associated to devices. Transcription: What issues arise if there are duplicate MAC addresses? MAC addresses are important. Let’s say I’m a PC … Continue reading What Happens when there are duplicate MAC Addresses. How many MAC Addresses can a Switch learn?