Brocade FastIron Ethernet Switch Platform and Layer 2 Switching Configuration Guide - Manual (Page 252)

Feature ICX 6430 ICX 6450 FCX ICX 6610 ICX 6650 FSX 800
FSX 1600 ICX 7750
Root Guard 08.0.01 08.0.01 08.0.01 08.0.01 08.0.01 08.0.01 08.0.10
Port statistics 08.0.01 08.0.01 08.0.01 08.0.01 08.0.01 08.0.01 08.0.10
Error disable recovery 08.0.01 08.0.01 08.0.01 08.0.01 08.0.01 08.0.01 08.0.10
STP overview
The Spanning Tree Protocol (STP) eliminates Layer 2 loops in networks, by selectively blocking some
ports and allowing other ports to forward traffic, based on global (bridge) and local (port) parameters
you can configure.
STP related features, such as RSTP and PVST, extend the operation of standard STP, enabling you
to fine-tune standard STP and avoid some of its limitations.
You can enable or disable STP on a global basis (for the entire device), a port-based VLAN basis (for
the individual Layer 2 broadcast domain), or an individual port basis.
Configuration procedures are provided for the standard STP bridge and port parameters.
Standard STP parameter configuration
Brocade 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 Brocade device runs a separate spanning tree (a separate
instance of STP). A Brocade device has one port-based VLAN (VLAN 1) by default that contains all
the device ports. Thus, by default each Brocade device has one spanning tree. However, if you
configure additional port-based VLANs on a Brocade 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
The following table lists the default STP states for Brocade devices.
Default STP states TABLE 43
Device type Default STP type Default STP state Default STP state of new VLANs 1
Switch image default STP 802.1d Enabled Enabled
Router image default No span Enabled Enabled
STP overview
252 FastIron Ethernet Switch Platform and Layer 2 Switching Configuration Guide
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