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Catalyst 6500 Series Switch Command Reference—Release7.6
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Chapter2 Catalyst 6500 Series Switch and ROM Monitor Commands
set spantree mode
set spantree mode
To configure the type of Spanning Tree Protocol mode to run, use the set spantree mode command.
set spantree mode {mistp | pvst+ | mistp-pvst+ | mst | rapid-pvst+}
Syntax Description
Defaults The default is PVST+.
Command Types Switch command.
Command Modes Privileged.
Usage Guidelines This command is not supported by the NAM.
When you connect through Telnet into a switch and try to change the spanning tree mo de fro m PV ST+
to MISTP or MISTP-PVST+, and no VLANs are mapped to any instance on that switch, this warning
message is displayed:
Console> (enable) set spantree mode mistp
Warning!! Changing the STP mode from a telnet session will disconnect the
session because there are no VLANs mapped to any MISTP instance.
Do you want to continue [n]?
When you connect through Telnet into a switch and try to change the spanning tree m ode f rom M ISTP
or MISTP-PVST+ to PVST+, or when you connect through Telnet into a switch and try to change the
spanning tree mode from PVST+ to MISTP or MISTP-PVST+ and additional VLAN-instance mappings
are on that switch, this warning message is displayed:
Console> (enable) set spantree mode pvst+
Warning!! Changing the STP mode from a telnet session might disconnect the
session.
Do you want to continue [n]?
When you change from MISTP to Rapid PVST+ and over 8000 VLAN ports are currently configured on
the switch, this warning message is displayed:
Console> (enable) set spantree mode rapid-pvst+
Warning!! This switch has 12345 VLAN-ports currently configured for STP.
Going out of MISTP mode could impact system performance.
Do you want to continue [n]?
mistp Specifies MISTP mode.
pvst+ Specifies PVST+ mode.
mistp-pvst+ Allows the switch running MISTP to tunnel BPDUs with remote switches
running PVST+.
mst Specifies MST mode.
rapid-pvst+ Specifies per VLAN Rapid Spanning Tree (IEEE 802.1w).