Alcatel OmniStack 6124, User Manual

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Spanning Tree Algorithm (STA)
3-19
STA Port Configuration
The following figure and table describe STA configuration for ports or modules.
Parameter Default Description
Fast Forwarding
Mode (All Ports)
Enabled See “Fast Forward” in this table.
Priority 128 Defines the priority for the use of a port in the STA algorithm. 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. Where more than one port is assigned the highest priority,
the port with lowest numeric identifier will be enabled.
The range is 0 - 255.
Path Cost 100/19/4 This parameter is used by the STA algorithm 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.
The default and recommended range is:
Standard Ethernet: 100 (50~600)
Fast Ethernet: 19 (10~60)
Gigabit Ethernet: 4 (3~10)
The full range is 1 - 65535.
Note: Path cost takes precedence over port priority.
Fast Forward Enabled This enables/disables Fast Forwarding for the selected port. In this mode,
ports skip the Blocked, Listening and Learning states and proceed
straight to Forwarding. Fast Forwarding enables end-node workstations
and servers to overcome time-out problems when the Spanning Tree
Algorithm is implemented in a network. Therefore, Fast Forwarding
should only be enabled for ports that are connected to an end-node
device.