User’s
Manual
45
the preferred path, link type to indicate a point-to-point connection or shared-media connection, and edge
port to indicate if the attached device can support fast forwarding.
3.2.1 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
Spanning Tree – Enables/disables STA on this interface. (Default: Enabled).
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 is enabled.
•
Default:
128
•
Range: 0-240, in steps of 16
Path Cost – This parameter is used by the STP 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 (see section
9.9.1)
, the maximum path cost is 65,535.
Range :
•
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
Admin Link Type – The link type attached to this interface.
Point-to-Point – A connection to exactly one other bridge.
Shared – A connection to two or more bridges.
