Operation Manual

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Port Role: Displays the role of the port played in the STP Instance.
 Root Port: Indicates the port that has the lowest path cost from
this bridge to the Root Bridge and forwards packets to the root.
 Designated Port: Indicates the port that forwards packets to a
downstream network segment or switch.
 Master Port: Indicates the port that connects a MST region to
the co
mmon root. The path from the master port to the
common root is the shortest path between this MST region and
the common root.
 Alternate Port: Indicates the port that can be a backup port of a
root or master port.
 Backup Port: Indicates the port that is the
backup port of a
designated port.

Disabled: Indicates the port that is not participating in the STP.
Port Status: Displays the working status of the port.
 Forwarding:
In this status the port can receive/forward data,
receive/send BPDU packets as well as learn MAC address.
 Learning:
In this status the port can receive/send BPDU
packets and learn MAC address.
 Blocking: In this status the port can only receive BPDU packets.
 Disconnected:
In this status the port is not participating in the
STP.
LAG:
Displays the LAG number which the port belongs to.
Note:
1. Configure the ports connected directly to terminals as edge ports and enable the BPDU
protection function as well. This not only enables these ports to transit to forwarding state
rapidly but also secures your network.
2. All the links of ports in a LAG can be configured as point-to-point links.
3. When the link of a port is configured as a point-to-point link, the spanning tree instances
owning this port are configured as point-to-point links. If the physical link of a port is not a
point-to-point link and you forcibly configure the link as a point-to-point link, temporary
loops may be incurred.
7.3 MSTP Instance
MSTP combines VLANs and spanning tree together via VLAN-to-instance mapping table
(VLAN-to-spanning-tree mapping). By adding MSTP instances, it binds several VLANs to an
instance to realize the load balance based on instances.
Only when the switches have the same MST region name, MST region revision and
VLAN-to-Instance mapping table, the switches can be regarded as in the same MST region.
The MSTP Instance function can be implemented on Region Config, Instance Config and
Instance Port Config pages.