Switch Port Config: Trunk + Native vs Hybrid + Native?

I had some very odd failures while running Trunk + Native VLAN.

I switched to Hybrid + Native VLAN and things started functioning as expected. I later found the “Tagged” option was allowing the function.

Is there a problem with Native VLAN mode on Trunk ports? If not, what is the purpose of the Native VLAN with Trunk mode if it is just tagged?

Thank you, Chris

1 Like

Hi Chris,

Please refer to the note below for the explanation of switchport modes on cnMatrix.

The native (or PVID) VLAN on trunk port is for processing incoming untagged frames. Trunk port always egresses tagged.


Thank you for that detail. The description does explain the major problems I was having with the cnPilot APs.

I am curious, what is the use case for a trunk port with a “native VLAN” that does not send untagged frames? The other switches that I use have “native VLANs” that work untagged in both directions, which makes sense to me.

Hi, the trunk port is typically used on uplink connection in which the link will carry traffic for all VLANs. The switch also supports hybrid mode which can egress untagged. However, hybrid port does not automatically become member of every VLAN, but the port must be manually added to the VLAN. For port with AP connection, it is recommended to use hybrid mode.
When connecting cnPilot AP to the switch, the feature Auto-VLAN (enabled by default) will detect the cnPilot’s presence, and communicate with cnPilot to get the VLANs and PVID to be conf on the port.

Thank you for the details. I do understand the use case for a trunk port, and for a trunk port with an actual native VLAN. I do not understand the use case for a trunk port that has a native VLAN option that leaves those frames tagged on exit, but adds tags to incoming packets to enter that VLAN.

1 Like

I had similar issues using trunk ports until I swapped to Hybrid + Native VLAN. Could a checkbox be added for tagging the Native VLAN just like the Hybrid port has?