D-Link DGS-3620-52P - Spanning Tree

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DGS-3620 Series Layer 3 Managed Stackable Gigabit Switch Web UI Reference Guide
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Figure 4-35 Layer 2 Protocol Tunneling Settings window
The fields that can be configured are described below:
Parameter Description
Layer 2 protocol
tunneling State
Use the radio buttons to enable or disable the layer 2 protocol tunneling function
globally on the Switch.
From Port / To Port
Select a range of ports to use in the configuration.
Type Use the drop-down menu to select the type of the ports. Available choices are UNI, NNI
and None. The default type is None.
Tunneled Protocol When UNI is selected in the Type drop-down menu, this drop-down menu shows the
following options:
STP- Specify the BPDU received on these UNI will be tunneled.
GVRP - Specify the GVRP PDU received on these UNI will be tunneled.
Protocol MAC - Specify the destination MAC address of the L2 protocol packets that will
tunneled on these UNI ports. At present, the MAC address can be 01-00-0C-CC-CC-CC
or 01-00-0C-CC-CC-CD.
All - Specify all supported.
Threshold (0-65535)
Enter the drop threshold for packets-per-second accepted on this UNI port. The port
drops the PDU if the protocol’s threshold is exceeded. The range of the threshold value
is 0 to 65535 (packet/second). The value 0 means unlimited. By default, the value is 0.
Click the Apply button to accept the changes made for each individual section.
Spanning Tree
This Switch supports three versions of the Spanning Tree Protocol: 802.1D-1998 STP, 802.1D-2004 Rapid STP,
and 802.1Q-2005 MSTP. 802.1D-1998 STP will be familiar to most networking professionals. However, since
802.1D-2004 RSTP and 802.1Q-2005 MSTP have been recently introduced to D-Link managed Ethernet switches,
a brief introduction to the technology is provided below followed by a description of how to set up 802.1D-1998 STP,
802.1D-2004 RSTP, and 802.1Q-2005 MSTP.
802.1Q-2005 MSTP
Multiple Spanning Tree Protocol, or MSTP, is a standard defined by the IEEE community that allows multiple
VLANs to be mapped to a single spanning tree instance, which will provide multiple pathways across the network.
Therefore, these MSTP configurations will balance the traffic load, preventing wide scale disruptions when a single
spanning tree instance fails. This will allow for faster convergences of new topologies for the failed instance.
Frames designated for these VLANs will be processed quickly and completely throughout interconnected bridges
utilizing any of the three spanning tree protocols (STP, RSTP or MSTP).
This protocol will also tag BPDU packets so receiving devices can distinguish spanning tree instances, spanning
tree regions and the VLANs associated with them. An MSTI ID will classify these instances. MSTP will connect
multiple spanning trees with a Common and Internal Spanning Tree (CIST). The CIST will automatically determine
each MSTP region, its maximum possible extent and will appear as one virtual bridge that runs a single spanning