switch to switch MAC address table populating

[sanju_baba]

I simply have two switches connected in packet tracer and despite clearing the MAC address table on both switches, they still populate the table with each other's MAC addresses. Why does this happen? I thought it might be via CDP but despite disabling the feature, the switches still learn each other's MAC addresses and I'm curious to know why. Thanks in advance for replies received.

[luis_cordova · Accepted solution]

Hi @sanju_baba ,

There is another control protocol that exchanges packets between the switches. One of these is SPT, which exchanges BPDU packets every two seconds. These BPDUs include the MAC address, so the switches continue to receive and learn the neighbor's MAC by this means.

In PacketTracer you can use the simulation mode to see the packages that are exchanged equipment.

Regards

[sanju_baba]

Hi Luis, thanks for clearing this up. I will give the simulation mode a try.

[Reza Sharifi]

CDP does not update MAC address. CDP runs on Cisco devices to discover information about neighboring devices such as device type capabilities, software version, remote port address, etc..

HTH