Extreme Networks ExtremeWare 7.2e, Installation And User Manual

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198 ExtremeWare 7.2e Installation and User Guide
Spanning Tree Protocol (STP)
Rapid Root Failover
ExtremeWare supports rapid root failover for faster STP failover recovery times in STP 802.1d mode. If
the active root port link goes down ExtremeWare recalculates STP and elects a new root port. Rapid root
failover allows the new root port to immediately begin forwarding, skipping the standard listening and
learning phases. Rapid root failover occurs only when the link goes down, and not when there is any
other root port failure, such as missing BPDUs.
The default setting is disabled. To enable rapid root failover, use the following command:
enable stpd <spanning tree name> rapid-root-failover
To display the configuration, use the following command:
show stpd {<spanning tree name> | detail}
STP Configurations
When you assign VLANs to an STPD, pay careful attention to the STP configuration and its effect on
the forwarding of VLAN traffic.
This section describes two types of STP configurations:
• Basic STP
• A VLAN that spans multiple STPDs
Basic STP Configuration
This section describes a basic, 802.1D STP configuration. Figure 31 illustrates a network that uses VLAN
tagging for trunk connections. The following four VLANs have been defined:
• Sales is defined on switch A, switch B, and switch M.
• Personnel is defined on switch A, switch B, and switch M.
• Manufacturing is defined on switch Y, switch Z, and switch M.
• Engineering is defined on switch Y, switch Z, and switch M.
• Marketing is defined on all switches (switch A, switch B, switch Y, switch Z, and switch M).
Two STPDs are defined:
• STPD1 contains VLANs Sales and Personnel.
• STPD2 contains VLANs Manufacturing and Engineering.
The VLAN Marketing is a member of both STPD1 and STPD2.