Unmanaged Switch Vlan Tags

For more information see what is a management vlan.

Unmanaged switch vlan tags.

As the following figure shows the switch connects to two different groups. Can afford to get a 30 switch that can understand vlans. Neither will it have knowledge of what vlan is the native the only one on the trunk that is not tagged vlan. The receiving switch will see the vlan tag and if the vlan is allowed it will forward the frame as required.

What an unmanaged switch that doesn t understand vlan tags will do with frames which have vlan tags a trunk link is really undefined. If all of the things plugged into an unmanaged switch are on the same vlan then you can do that. For example a broadcast may be received on vlan 10. So what would happen if one put it in on a trunk.

However if you have a mix of vlans on a switch it needs to be managed. What happens is when a trunk is confgured a header aka tag which varies in size depending on what encapsulation is used is added to the front of the a frame by doing this the destination knows which vlan it belongs when it arrives. You must add the lag to the vlan as a single unit. Well in my mind either the native vlan.

A lan can be divided into several vlans logically and only the hosts in a same vlan can communicate with each other. If a port is a member of a link aggregation group lag or you plan to add it to a lag do not add it to a vlan or tag it individually. Running tags over a dumb switch just amounts to running multiple layer 3 on the layer 2 there is zero lack of. Vlan virtual local area network is a technology that can solve broadcasting issues.

Simply put the unmanaged switch would not be able to know what vlans it would or would not send over the link that might or might not be a trunk. Some switches will drop the frames as garbled some switches will pass them on as they are and some switches will strip the vlan tags. Vlan 1 is also the management vlan on switches that support management vlans. Here you can see this process in action.

Here are two configuration examples for 802 1q vlan.