SMC Networks SMC7724M/VSW manual Forwarding Tagged/Untagged Frames

VLAN CONFIGURATION

groups it wants to join. When this switch receives these messages, it will automatically place the receiving port in the specified VLANs and forward the message to all other ports. When the message arrives at another switch that supports GVRP, it will also place the receiving port in the specified VLANs and pass the message on to all other ports. VLAN requirements are propagated in this way throughout the network. This allows GVRP-compliant devices to be automatically configured for VLAN groups based solely on endstation requests.

To implement GVRP in a network, you must first configure the static VLANs required on switches that are connected to PCs, servers, and other devices, so that these VLANs can be propagated across the network (Web - VLAN/VLAN Static Membership.) For other core switches in the network, enable GVRP on the links between these devices.

(Web - VLAN/Port Configuration or Trunk Configuration.)

Forwarding Tagged/Untagged Frames

If you want to create a small port-based VLAN for devices attached directly to a single switch, you can assign ports to the same untagged VLAN. However, to participate in a VLAN group that crosses several switches, you need to create a VLAN for that group and enable tagging on all ports.

Ports can be assigned to multiple tagged or untagged VLANs. Each port on the switch is therefore capable of passing tagged or untagged frames. To forward a frame from a VLAN-aware device to a VLAN-unaware device, the switch first decides where to forward the frame, and then strips off the VLAN tag. However, to forward a frame from a VLAN-unaware device to a VLAN-aware device, the switch first decides where to forward the frame, and then inserts a VLAN tag reflecting this port’s default VID.

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