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Community Member

Source mac not being added with Vlans in packet tracer


I was doing a Lab in packet tracer:

two switches (2960's) and 3 end devices. On sw1 pc1 is connected to int fa0/11 and pc 3 is connected to int fa0/13. Both int belong to vlan 11 & 13

On sw2 PC 2 is connected to fa0/12 also belonging to vlan 11.

In this set up I can ping all devices. However the only mac address being added to the mac table are the def. int macs of each switches port. When I remove all int from vlan 11 & 13 and add them to native vlan 1 mac's are being added to the table.

Am I doing something wrong, or is this a flaw with Packet tracer.

Community Member

Source mac not being added with Vlans in packet tracer

Hi Devin,

PT is fine there is no bug regarding this. You might already know that the MAC-table is refreshed for every 300 sec's, eliminating the records of unused mac's.So i think you probably have checked it after the flush.

Replica of your topolgy:

I replicated your topology and seen that the switches are learning MAC address appropriatley along with their VLANs. I've attached the topolgy.

Here is the VLAN config on switch1:

Here is the VLAN config on switch2:

The ports (Fa0/1)connected the both switches are configured to be trunk.

On switch1: PC0 (Fa0/11) is in vlan11 ( and PC1(Fa0/13) is in vlan13 (

On switch2: PC2 (Fa0/12) is in vlan11 ( There is no device on Switch2 for vlan13.

As you said, at first both switches will learn the mac's of the ports that are joining them.

Now if i ping PC0( from PC2(, then both the switches are learning the source mac and destination mac.

MAC table of Switch1:

Here it learned the MAC of PC2(000c.8518.9115) and the MAC of PC0(000a.411c.2132).

MAC table of Switch2:

Here it learned the source mac i.e, PC2 (000c.8518.9115) and the destination MAC i.e. PC0(


After 300 sec's if the devices won't communicate then the MAC of PC0 & PC2 from  both the switches will be eliminated.

Please find attachment for the live topology.



Regards, Chandu
Community Member

Source mac not being added with Vlans in packet tracer

Please rate if you find it helpful.

Regards, Chandu
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