Extreme Networks ExtremeWare XOS Command Reference Manual page 1216

ExtremeWare XOS 11.5 supports only the Summit X450 family of switches and the BlackDiamond 8800 series switch.
STP Commands
If you configure MSTP, you do not need a carrier VLAN. With MSTP, you configure a CIST that controls
the connectivity of interconnecting MSTP regions and sends BPDUs across the regions to communicate
the status of MSTP regions. All VLANs participating in the MSTP region have the same privileges.
Protected VLAN. Protected VLANs are all other VLANs that are members of the STPD. These VLANs
"piggyback" on the carrier VLAN. Protected VLANs do not transmit or receive STP BPDUs, but they
are affected by STP state changes and inherit the state of the carrier VLAN. Protected VLANs can
participate in multiple STPDs, but any particular port in the VLAN can belong to only one STPD.
Enabling autobind on a protected VLAN does not expand the boundary of the STPD. However, the
VLAN and port combinations are added to or removed from the STPD subject to the boundaries of the
carrier VLAN.
If you configure MSTP, all member VLANs in an MSTP region are protected VLANs. These VLANs do
not transmit or receive STP BPDUs, but they are affected by STP state changes communicated by the
CIST to the MSTP regions. MSTIs cannot share the same protected VLAN; however, any port in a
protected VLAN can belong to multiple MSTIs.
Automatically Inheriting Ports—MSTP Only. In an MSTP environment, whether you manually or
automatically bind a port to an MSTI in an MSTP region, the switch automatically binds that port to the
CIST. The CIST handles BPDU processing for itself and all of the MSTIs; therefore, the CIST must inherit
ports from the MSTIs in order to transmit and receive BPDUs. You can only delete ports from the CIST
if the port is no longer a member of an MSTI.
Displaying STP Information. To view STP configuration status of the ports on a VLAN, use the following
command:
show vlan <vlan_name> stpd
Example
The examples in this section assume that you have already removed the ports from the Default VLAN.
To automatically add ports to an STPD running 802.1D, EMISTP, or PVST+ and to expand the boundary
of the STPD, you must complete the following tasks:
Create the carrier VLAN.
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Assign a VLANid to the carrier VLAN.
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Add ports to the carrier VLAN.
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Create an STPD (or use the default, S0).
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Enable autobind on the STPDs carrier VLAN.
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Configure the STPD tag (the StpdID must be identical to the VLANid of the carrier VLAN in the STP
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domain).
Enable STP.
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ExtremeWare XOS 11.5 Command Reference Guide