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networkingpacketswitchingvlan

Vlan packet passing through over a layer 2 switch

I've got a unmanaged switch in my network and I would like to know if it will pass on vlan encapsulated packets still. Would it understand it?

I have vlan capable hardware on each side of the L2 Switch. A basic map would look like:

Modem > VlanRouter > L2Switch > L3Switch

Does the packet get all the way through?

Solution

  • I've got a unmanaged switch in my network and I would like to know if it will pass on vlan encapsulated packets still.

    Many unmanaged switches pass VLAN-tagged frames transparently, but not all do. An unmanaged, yet IEEE 802.1D-compliant switch drops all tagged frames.

    Would it understand it?

    No. They're just frames for it.

    You should be aware that if a switch just transparently forwards VLAN-tagged frames by MAC address it might cause those frames leaking between VLANs even to a point of working connections - depending on the configuration and implementation of VLANs on the connected managed switches. Generally, trying to use tagged frames across unmanaged switches is a bad idea.