Configuring Port Priority; Port Priority On Link Aggregate Ports - Alcatel OmniSwitch 6624 Network Configuration Manual

Configuring Spanning Tree Parameters
For more information about configuring an aggregate of ports, see
Aggregation," and Chapter 11, "Configuring Dynamic Link Aggregation."
To view the port STP status, use the
command, see the OmniSwitch CLI Reference Guide.

Configuring Port Priority

A bridge port is identified within the Spanning Tree by its Port ID (a 16-bit hex number). The first 4 bits
of the Port ID contain a priority value and the remaining 12 bits contain the physical switch port number.
The port priority is used to determine which port offers the best path to the root when multiple paths have
the same path cost. The port with the highest priority (lowest numerical priority value) is selected and the
others are put into a blocking state. If the priority values are the same for all ports in the path, then the port
with the lowest physical switch port number is selected.
By default, STP is enabled on a port and the port priority is set to 7. If the switch is running in the 1x1
Spanning Tree mode, then the port priority applies to the specified VLAN STP instance associated with
the port. If the switch is running in the flat Spanning Tree mode, then the port priority applies across all
VLANs associated with the port. VLAN 1 is referenced as the port's VLAN, even if the port is associated
with other VLANs.
To change the port priority, enter bridge followed by an existing VLAN ID (or VLAN 1 if using a flat
Spanning Tree instance) then the port's slot/port designation followed by priority and a numerical value
between 0 and 15 for the priority value. For example, the following command sets the priority for port 1
on slot 8 for VLAN 10 to 3:
-> bridge 10 8/1 priority 3

Port Priority on Link Aggregate Ports

Physical ports that belong to a link aggregate do not participate in the Spanning Tree Algorithm. Instead,
the algorithm is applied to the aggregate logical link (virtual port) that represents a collection of physical
ports. To change the STP port priority for a link aggregate, use the same bridge command, but specify a
link aggregate control number instead of a slot and port. For example, the following command sets the
priority for link aggregate 29 associated with VLAN 755 to 9:
-> bridge 755 29 priority 9
For more information about configuring an aggregate of ports, see
Aggregation," and Chapter 11, "Configuring Dynamic Link Aggregation."
To view the STP priority for a port, use the
this command, see the OmniSwitch CLI Reference Guide.
OmniSwitch 6624/6648 Network Configuration Guide
show spantree ports command. For more information about this
show spantree ports
April 2004
Configuring STP Port Parameters
Chapter 10, "Configuring Static Link
Chapter 10, "Configuring Static Link
command. For more information about
page 5-15