Spanning Tree; 802.1S Mstp - D-Link DGS-3048 - Switch Product Manual

The following parameters can be set:
Parameter
VID
Multicast MAC
Address
Port Settings
Click Apply to implement the changes made. To delete an entry in the Static Multicast Forwarding Table, click the
corresponding under the Delete heading. Click the Show All Multicast Forwarding Entries link to return to the Static
Multicast Forwarding Settings window.

Spanning Tree

This Switch supports three versions of the Spanning Tree Protocol; 802.1d STP, 802.1w Rapid STP and 802.1s MSTP.
802.1d STP will be familiar to most networking professionals. However, since 802.1w RSTP and 802.1s MSTP has 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 STP, 802.1w RSTP and 802.1s MSTP.

802.1s 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 either of the three spanning tree
protocols (STP, RSTP or MSTP).
This protocol will also tag BDPU packets so receiving devices can distinguish spanning tree instances, spanning tree regions
and the VLANs associated with them. These instances will be classified by an MSTI ID. 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 tree. Consequentially,
frames assigned to different VLANs will follow different data routes within administratively established regions on the
network, continuing to allow simple and full processing of frames, regardless of administrative errors in defining VLANs
and their respective spanning trees.
Each switch utilizing the MSTP on a network will have a single MSTP configuration that will have the following three
attributes:
1. A configuration name defined by an alphanumeric string of up to 32 characters (defined in the Current MST
Configuration Identification window in the Configuration Name field).
2. A configuration revision number (named here as a Revision Level (0-65535) and found in the Current MST
Configuration Identification window) and;
3. A 4096-element table (defined here as a VID List in the Current MST Configuration Identification window)
that will associate each of the possible 4096 VLANs supported by the Switch for a given instance.
To utilize the MSTP function on the Switch, three steps need to be taken:
1. The Switch must be set to MSTP (found in the STP Bridge Global Settings window in the STP Version field)
2. The correct spanning tree priority for the MSTP instance must be entered (defined here as a Priority in the STP
Instance Table window when configuring the settings for an MSTI ID).
DGS-3048 Gigabit Ethernet Switch Manual
Description
The VLAN ID of the VLAN the corresponding MAC address belongs to.
The MAC address of the static source of multicast packets. This must be a multicast
MAC address.
Allows the selection of ports that will be members of the static multicast group and
ports that are either forbidden from joining dynamically, or that can join the multicast
group dynamically, using GMRP. The options are:
None - No restrictions on the port dynamically joining the multicast group. When None
is chosen, the port will not be a member of the Static Multicast Group.
Egress - The port is a static member of the multicast group.
62