Brocade FastIron Ethernet Switch Platform and Layer 2 Switching Configuration Guide - Manual (Page 302)

The priority value parameter specifies the priority of the bridge. You can enter a value from 0 - 65535.
A lower numerical value means the bridge has a higher priority. Thus, the highest priority is 0. The
default is 32768.
You can specify some or all of these parameters on the same command line. If you specify more than
one parameter, you must specify them in the order shown above, from left to right.
Changing port parameters
The 802.1W port commands can be enabled on individual ports or on multiple ports, such as all ports
that belong to a VLAN.
The 802.1W port parameters are preconfigured with default values. If the default parameters meet
your network requirements, no other action is required.
You can change the following 802.1W port parameters using the following method.
device(config)#vlan 10
device(config-vlan-10)#spanning-tree 802-1w ethernet 5 path-cost 15 priority 64
Syntax: spanning-tree 802-1w ethernet port path-cost value | priority value | [admin-edge-port] |
[admin-pt2pt-mac] | [force-migration-check]
The path-cost value parameter specifies the cost of the port path to the root bridge. 802.1W prefers
the path with the lowest cost. You can specify a value from 1 - 20,000,000. The following table shows
the recommended path cost values from the IEEE standards.
Recommended path cost values of 802.1W TABLE 48
Link speed Recommended (Default) 802.1W
path cost values Recommended 802.1W patch cost
range
Less than 100 kilobits per second 200,000,000 20,000,000 – 200,000,000
1 Megabit per second 20,000,000 2,000,000 – 200,000,000
10 Megabits per second 2,000,000 200,000 – 200,000,000
100 Megabits per second 200,000 20,000 – 200,000,000
1 Gbps per second 20,000 2,000 – 200,000,000
10 Gbps per second 2,000 200 – 20,000
100 Gbps per second 200 20 – 2,000
1 Terabits per second 20 2 – 200
10 Terabits per second 2 1 – 20
• You can specify a value from 0 – 240, in increments of 16. If you enter a value that is not divisible
by 16, the software returns an error message. The default value is 128. A higher numerical value
means a lower priority; thus, the highest priority is 0.
• Set the admin-edge-port to enabled or disabled. If set to enabled, then the port becomes an edge
port in the domain.
Set the admin-pt2pt-mac to enabled or disabled. If set to enabled, then a port is connected to another
port through a point-to-point link. The point-to-point link increases the speed of convergence. This
parameter, however, does not auto-detect whether or not the link is a physical point-to-point link.
The force-migration-check parameter forces the specified port to sent one RST BPDU. If only STP
BPDUs are received in response to the sent RST BPDU, then the port will go return to sending STP
BPDUs.
Spanning Tree Protocol
302 FastIron Ethernet Switch Platform and Layer 2 Switching Configuration Guide
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