Configuring Standard Stp Parameters; Stp Parameters And Defaults - Dell PowerConnect B-FCXs Configuration Manual

8

Configuring standard STP parameters

Configuring standard STP parameters
Layer 2 Switches and Layer 3 Switches support standard STP as described in the IEEE 802.1D
specification. STP is enabled by default on Layer 2 Switches but disabled by default on Layer 3
Switches.
By default, each port-based VLAN on a Dell PowerConnect device runs a separate spanning tree (a
separate instance of STP). A Dell PowerConnect device has one port-based VLAN (VLAN 1) by
default that contains all the device ports. Thus, by default each Dell PowerConnect device has one
spanning tree. However, if you configure additional port-based VLANs on a Dell PowerConnect
device, then each of those VLANs on which STP is enabled and VLAN 1 all run separate spanning
trees.
If you configure a port-based VLAN on the device, the VLAN has the same STP state as the default
STP state on the device. Thus, on Layer 2 Switches, new VLANs have STP enabled by default. On
Layer 3 Switches, new VLANs have STP disabled by default. You can enable or disable STP in each
VLAN separately. In addition, you can enable or disable STP on individual ports.

STP parameters and defaults

Table 47
TABLE 47
Device type
Layer 2 Switch
Layer 3 Switch
1.
device. The new VLAN does not inherit the STP state of the default VLAN.
2.
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
Table 48
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.
TABLE 48
Parameter
Forward Delay
Maximum Age
208
lists the default STP states for Dell PowerConnect devices.
Default STP states
Default STP type
MSTP
MSTP
When you create a port-based VLAN, the new VLAN STP state is the same as the default STP state on the
MSTP stands for "Multiple Spanning Tree Protocol". In this type of STP, each port-based VLAN, including the
"Single Spanning Tree (SSTP)"
lists the default STP bridge parameters. The bridge parameters affect the entire spanning
Default STP bridge parameters
Description
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.
The interval a bridge will wait for a configuration BPDU
from the root bridge before initiating a topology change.
Default STP state
2
Enabled
Disabled
on page 269.
Default STP state of new
1
VLANs
Enabled
Disabled
Default and valid values
15 seconds
Possible values: 4 – 30
seconds
20 seconds
Possible values: 6 – 40
seconds
PowerConnect B-Series FCX Configuration Guide
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