Encapsulation Modes - Extreme Networks ExtremeWare XOS Command Reference Manual

ExtremeWare XOS 11.5 supports only the Summit X450 family of switches and the BlackDiamond 8800 series switch.
CIST to the MSTP regions. MSTIs cannot share the same protected VLAN; however, any port in a
protected VLAN can belong to multiple MSTIs.
STPD Modes
An STPD has three modes of operation:
802.1D mode
●
Use this mode for backward compatibility with previous STP versions and for compatibility with
third-party switches using IEEE standard 802.1D. When configured in this mode, all rapid
configuration mechanisms are disabled.
802.1w mode
●
Use this mode for compatibility with Rapid Spanning Tree (RSTP). When configured in this mode,
all rapid configuration mechanisms are enabled. The benefit of this mode is available on point-to-
point and edge ports only.
You enable or disable RSTP on a per STPD basis only. You do not enable RSTP on a per port basis.
MSTP mode
●
Use this mode for compatibility with Multiple Spanning Tree (MSTP, 802.1s). MSTP is an extension
of RSTP and offers the benefit of better scaling with fast convergence. When configured in this mode,
all rapid configuration mechanisms are enabled. The benefit of MSTP is available only on point-to-
point links and when you configure the peer in MSTP or 802.1w mode. If you do not select point-to-
point links and the peer is not configured in 802.1w mode, the STPD fails back to 802.1D mode.
You can create only one MSTP region on the switch, and all switches that participate in the region
must have the same regional configurations. You enable or disable an MSTP on a per STPD basis
only. You do not enable MSTP on a per port basis.
By default, the:
STPD operates in 802.1D mode.
●
Default device configuration contains a single STPD called s0.
●
Default VLAN is a member of STPD s0 with autobind enabled.
●
All STP parameters default to the IEEE 802.1D values, as appropriate.

Encapsulation Modes

You can configure ports within an STPD to accept and transmit specific BPDU encapsulations. This STP
port encapsulation is separate from the STP mode of operation. For example, you can configure a port
to accept the PVST+ BPDU encapsulation while running in 802.1D mode.
An STP port has three possible encapsulation modes:
802.1D mode
●
This mode is used for backward compatibility with previous STP versions and for compatibility with
third-party switches using IEEE standard 802.1D. BPDUs are sent untagged in 802.1D mode. Because
of this, any given physical interface can have only one STPD running in 802.1D mode.
This encapsulation mode supports the following STPD modes of operation: 802.1D, 802.1w, and
MSTP.
ExtremeWare XOS 11.5 Command Reference Guide
1165