Brocade TurboIron 24X Series Configuration Guide - Manual (Page 546)

512 Brocade TurboIron 24X Series Configuration Guide
53-1003053-01
Configuring standard STP parameters
STP parameters and defaults
Table 85 lists the default STP states.
Table 86 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, Brocade 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 87 lists the default STP port parameters. The port parameters affect individual ports and are
separately configurable on each port.
TABLE 85 Default STP states
Device type Default STP type Default STP state Default STP state of new
VLANs
1
1. When you create a port-based VLAN, the new VLAN STP state is the same as the default STP state on the
device. The new VLAN does not inherit the STP state of the default VLAN.
Layer 2 Switch MSTP 2
2. MSTP stands for “Multiple Spanning Tree Protocol”. In this type of STP, each port-based VLAN, including the
default VLAN, has its own spanning tree. References in this documentation to “STP” apply to MSTP. The Single
Spanning Tree Protocol (SSTP) is another type of STP. SSTP includes all VLANs on which STP is enabled in a single
spanning tree. Refer to
“Single Spanning Tree (SSTP)” on page 566.
Enabled Enabled
Layer 3 Switch MSTP Disabled Disabled
TABLE 86 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