In Cisco packet tracer, when I connect 2 switches together, the CAM table on each switch gives the MAC address of the switch port of the other switch.
This is surprising to me, and it really threw me off when I was playing with port-security (the maximum number of MAC addresses was reached, which triggered a violation, and I could not figure out why. It turns out I was not accounting for the MAC address of a directly connected switch port). I am relieved that I understand now, my questions are:
- Why / How (what protocol) did they learn the mac address of the switch port on the other end? Perhaps something to do with auto-negotiation? Do they ping each other (I don’t suppose this can happen without IP’s assigned on VLAN interface?)
- Is this perhaps an action by packet tracer and this would not be reflected with real switches?