Solved: Wrong vlan ID configuration causes MAC address learning

palani2010 · ‎07-04-2022

Wrong vlan ID configuration causes MAC address learning

Example -Interface eth1/2 is configured on vlan id 10 and is connected to a different vlan's end host. Will I be able to learn the MAC Address from the ethernet1/2 interface?

Jon Marshall · ‎07-04-2022

The switch will record the mac address of the end device against eth1/2 so yes it will be learnt.

But the switch will allocate it to the vlan the interface is in so if it is in the wrong then it will not be able communicate with other devices in the same IP subnet.

Jon

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Jon Marshall · ‎07-04-2022

The switch will record the mac address of the end device against eth1/2 so yes it will be learnt.

But the switch will allocate it to the vlan the interface is in so if it is in the wrong then it will not be able communicate with other devices in the same IP subnet.

Jon

Leo Laohoo · ‎07-04-2022

In reality, the answer is dependent entirely on how badly coded the wired NIC is.

In the medical industry, there are large variet of IoT (Internet of Trash) clients with poorly written NIC codes. I regularly troubleshoot this exact scenario (client is put into the wrong VLAN) and the wired client will stop talking MAC address.