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Catalyst 6500 Series Switch Software Configuration Guide—Release 8.7
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Chapter 7 Configuring Spanning Tree
Configuring MISTP-PVST+ or MISTP on the Switch
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Console> (enable)
Configuring MISTP-PVST+ or MISTP on the Switch
The default spanning-tree mode on the Catalyst 6500 series switches is Rapid-PVST+ mode. If you want
to use MISTP mode in your network, we recommend that you carefully follow the procedures that are
described in the following sections in order to avoid losing connectivity in your network.
When you change the spanning-tree mode, the current mode stops, the information collected at runtime is
used to build the port database for the new mode, and the new spanning-tree mode restarts the computation
of the active topology. Information about the port states is lost; however, all of the configuration
parameters are preserved for the previous mode. If you return to the previous mode, the configuration is
still there.
Note
We recommend that if you use MISTP mode, you should configure
all
of your Catalyst 6500 series
switches to run MISTP.
To use MISTP mode, you first enable an MISTP instance and then map at least one VLAN to the
instance. You must have at least one forwarding port in the VLAN in order for the MISTP instance to be
active.
Note
Map VLANs to MISTP instances on Catalyst 6500 series switches that are either in VTP server mode or
transparent mode only. You cannot map VLANs to MISTP instances on switches that are in VTP client
mode. To avoid VTP configuration errors that could cause problems with your MISTP configuration,
see
Chapter 10, “Configuring VTP”
for detailed information on using VTP versions 1, 2, and 3.
If you are changing a switch from PVST+ mode to MISTP mode and you have other switches in the
network that are using PVST+, you must first enable MISTP-PVST+ mode on each switch on which you
intend to use MISTP so that PVST+ BPDUs can flow through the switches while you configure them.
When all switches in the network are configured in MISTP-PVST+, you can then enable MISTP on all
of the switches.
These sections describe how to use MISTP-PVST+ or MISTP:
•
Default MISTP and MISTP-PVST+ Configuration, page 7-35
•
Setting the MISTP-PVST+ Mode or the MISTP Mode, page 7-35
•
Configuring an MISTP Instance, page 7-37
•
Enabling an MISTP Instance, page 7-41
