Foundry Networks FESX User Manual

Configuring Spanning Tree Protocol (STP) and IronSpan Features
December 2005 © Foundry Networks, Inc. 7 - 3
Table 7.3 lists the default STP bridge parameters. The bridge parameters affect the entire spanning tree. If you
are using MSTP, the parameters affect the VLAN. If you are using SSTP, the parameters affect all VLANs that are
members of the single spanning tree.
NOTE: If you plan to change STP bridge timers, Foundry recommends that you stay within the following ranges,
from section 8.10.2 of the IEEE STP specification.
2 * (forward_delay -1) >= max_age
max_age >= 2 * (hello_time +1 )
Table 7.4 lists the default STP port parameters. The port parameters affect individual ports and are separately
configurable on each port.
Table 7.3: Default STP Bridge Parameters
Parameter Description Default and Valid Values
Forward Delay The period of time spent by a port in the listening and
learning state before moving on to the learning or
forwarding state, respectively.
The forward delay value is also used for the age time of
dynamic entries in the filtering database, when a
topology change occurs.
15 seconds
Possible values: 4 – 30
seconds
Maximum Age The interval a bridge will wait for a configuration BPDU
from the root bridge before initiating a topology change.
20 seconds
Possible values: 6 – 40
seconds
Hello Time The interval of time between each configuration BPDU
sent by the root bridge.
2 seconds
Possible values: 1 – 10
seconds
Priority A parameter used to identify the root bridge in a
spanning tree (instance of STP). The bridge with the
lowest value has the highest priority and is the root.
A higher numerical value means a lower priority; thus,
the highest priority is 0.
32768
Possible values: 0 – 65535
Table 7.4: Default STP Port Parameters
Parameter Description Default and Valid Values
Priority The preference that STP gives this port relative to other
ports for forwarding traffic out of the spanning tree.
A higher numerical value means a lower priority; thus,
the highest priority is 8.
128
Possible values: 8 – 252
(configurable in increments
of 4)

Foundry Networks FESX Specifications

General

Brand	Foundry Networks
Model	FESX
Category	Switch
Language	English