PLANET SGSD-1022 - Manual (Page 172)

User’s Manual of SGSD-1022 / SGSD-1022P
SGSW-2840 / SGSW-2840P
The page includes the following fields:
Object Description
• STA State Displays current state of this port within the Spanning Tree. (See “Displaying
Interface Settings” on page 3-156 for additional information.)
-Discarding – Port receives STA configuration messages, but does not forward
packets.
-Learning – Port has transmitted configuration messages for an interval set by
the Forward Delay parameter without receiving contradictory information. Port
address table is cleared, and the port begins learning addresses.
-Forwarding – Port forwards packets, and continues learning addresses.
• Trunk Indicates if a port is a member of a trunk. (STA Port Configuration only)
• MST Instance ID Instance identifier to configure.
(Default: 0)
• Priority Defines the priority used for this port in the Spanning Tree Protocol. If the path
cost for all ports on a switch are the same, the port with the highest priority (i.e.,
lowest value) will be configured as an active link in the Spanning Tree. This
makes a port with higher priority less likely to be blocked if the Spanning Tree
Protocol is detecting network loops. Where more than one port is assigned the
highest priority, the port with lowest numeric identifier will be enabled.
Range: 0-240, in steps of 16;
Default: 128
• Admin MST Path Cost This parameter is used by the MSTP to determine the best path between
devices. Therefore, lower values should be assigned to ports attached to faster
media, and higher values assigned to ports with slower media. (Path cost takes
precedence over port priority.)
Note that when the Path Cost Method is set to short, the maximum path cost is
65,535.
By default, the system automatically detects the speed and duplex mode used on each port, and configures the path cost
according to the values shown below. Path cost “0” is used to indicate auto-configuration mode. When the short path cost
method is selected and the default path cost recommended by the IEEE 8021w standard exceeds 65,535, the default is set to
65,535.
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