Foundry Networks FESX User Manual

Foundry Configuration Guide for the FESX, FSX, and FWSX
7 - 6 © Foundry Networks, Inc. December 2005
The priority <value> parameter specifies the priority and can be a value from 0 – 65535. A higher numerical
value means a lower 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 STP Port Parameters
To change the path and priority costs for a port, enter commands such as the following:
FESX424 Router(config)# vlan 10
FESX424 Router(config-vlan-10)# spanning-tree ethernet 5 path-cost 15 priority 64
Syntax: spanning-tree ethernet [<slotnum>/]<portnum> path-cost <value> | priority <value> | disable | enable
The <portnum> parameter specifies the interface. If you are configuring a chassis device, specify the slot number
as well as the port number (<slotnum>/<portnum>).
The path-cost <value> parameter specifies the port’s cost as a path to the spanning tree’s root bridge. STP
prefers the path with the lowest cost. You can specify a value from 0 – 65535.
The default depends on the port type:
• 10 Mbps – 100
• 100 Mbps – 19
• Gigabit – 4
• 10 Gigabit – 2
The priority <value> parameter specifies the preference that STP gives this port relative to other ports for
forwarding traffic out of the spanning tree. You can specify a value from 8 – 252, in increments of 4. If you enter a
value that is not divisible by four the software rounds to the nearest value that is. The default is 128. A higher
numerical value means a lower priority; thus, the highest priority is 8.
NOTE: If you are upgrading a device that has a configuration saved under an earlier software release, and the
configuration contains a value from 0 – 7 for a port’s STP priority, the software changes the priority to the default
when you save the configuration while running the new release.
The disable | enable parameter disables or re-enables STP on the port. The STP state change affects only this
VLAN. The port’s STP state in other VLANs is not changed.
STP Protection Enhancement
STP protection provides the ability to prohibit an end station from initiating or participating in an STP topology
change.
The 802.1W Spanning Tree Protocol (STP) detects and eliminates logical loops in a redundant network by
selectively blocking some data paths (ports) and allowing only the best data paths to forward traffic.
In an STP environment, switches, end stations, and other Layer 2 devices use Bridge Protocol Data Units
(BPDUs) to exchange information that STP will use to determine the best path for data flow. When a Layer 2
device is powered ON and connected to the network, or when a Layer 2 device goes down, it sends out an STP
BPDU, triggering an STP topology change.
In some instances, it is unnecessary for a connected device, such as an end station, to initiate or participate in an
STP topology change. In this case, you can enable the STP Protection feature on the Foundry port to which the
end station is connected. Foundry’s STP Protection feature disables the connected device’s ability to initiate or
participate in an STP topology change, by dropping all BPDUs received from the connected device.
Configuration Notes
This feature is supported in the following configurations:
• FESX devices running software release 02.1.01 or later
• All FSX and FWSX devices and associated software releases

Foundry Networks FESX Specifications

General

Brand	Foundry Networks
Model	FESX
Category	Switch
Language	English