Netgear XCM8806 - 8800 SERIES 6-SLOT CHASSIS SWITCH ハードウェアマニュアル

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.

Multiple Instance Spanning Tree Protocol (EMISTP) mode

EMISTP mode is proprietary to NETGEAR and is an extension of STP that allows a 
physical port to belong to multiple STPDs by assigning the port to multiple VLANs. 
EMISTP adds significant flexibility to STP network design. BPDUs are sent with an 
802.1Q tag having an STPD instance Identifier (STPD ID) in the VLAN ID field.

This encapsulation mode supports the following STPD modes of operation: 802.1D and 
802.1w.

Per VLAN Spanning Tree (PVST+) mode

This mode implements PVST+ in compatibility with third-party switches running this 
version of STP. The STPDs running in this mode have a one-to-one relationship with 
VLANs, and send and process packets in PVST+ format. 

This encapsulation mode supports the following STPD modes of operation: 802.1D and 
802.1w.