User`s manual

User’s Manual 51
Field Attributes
Read Only Attributes
STA State – Displays current state of this port within the Spanning Tree. (For more information, refer to
section 3.1.5 Displaying Interface Settings.)
• 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)
Configuration Attributes
MST Instance ID – Instance identifier to configure. (Range: 0-4094; 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 (For example, 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.
• Default: 128
• Range: 0-240, in steps of 16
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 (section 9.9.1), the maximum path cost is 65,535.
Range:
• Ethernet: 200,000-20,000,000
• Fast Ethernet: 20,000-2,000,000
• Gigabit Ethernet: 2,000-200,000
Default:
• Ethernet – Half duplex: 2,000,000; full duplex: 1,000,000; trunk: 500,000
• Fast Ethernet – Half duplex: 200,000; full duplex: 100,000; trunk: 50,000
• Gigabit Ethernet – Full duplex: 10,000; trunk: 5,000
Configuring Switch Using the Web or CLI
Web
Click Spanning Tree – MSTP, Port Configuration or Trunk Configuration. Enter the priority and path
cost for an interface, and click Apply.