Netgear XCM8810 - 8800 SERIES 10-SLOT CHASSIS SWITCH ハードウェアマニュアル

These encapsulation modes are for STP ports, not for physical ports. When a physical port 
belongs to multiple STPDs, it is associated with multiple STP ports. It is possible for the 
physical port to run in different modes for different domains to which it belongs.

MSTP STPDs use only 802.1D BPDU encapsulation mode. The switch prevents you from 
configuring EMISTP or PVST+ encapsulation mode for MSTP STPDs. 

STP Rules and Restrictions

This section summarizes the rules and restrictions for configuring STP as follows:

The carrier VLAN must span all ports of the STPD. (This is not applicable to MSTP.)

The STPD ID must be the VLAN ID of the carrier VLAN; the carrier VLAN cannot be 

partitioned. (This is not applicable to MSTP.)

A default VLAN cannot be partitioned. If a VLAN traverses multiple STPDs, the VLAN 

must be tagged.

An STPD can carry, at most, one VLAN running in PVST+ mode, and its STPD ID must 

be identical with that VLAN ID. In addition, the PVST+ VLAN cannot be partitioned.

The default VLAN of a PVST+ port must be identical with the native VLAN on the PVST+ 

device connected to that port.

If an STPD contains both PVST+ and non-PVST+ ports, that STPD must be enabled. If 

that STPD is disabled, the BPDUs are flooded in the format of the incoming STP port, 
which may be incompatible with those of the connected devices.

The 802.1D ports must be untagged; and the EMISTP/PVST+ ports must be tagged in 

the carrier VLAN.

An STPD with multiple VLANs must contain only VLANs that belong to the same virtual 

router instance. 

STP and network login operate on the same port as follows:

STP (802.1D), RSTP (802.1W), and MSTP (802.1S) support both network login and 

STP on the same port.

At least one VLAN on the intended port should be configured both for STP and 

network login.

When STP blocks a port, network login does not process authentication requests and 
BPDUs are the only traffic in and out of the port. All user data forwarding stops.

When STP places a port in forwarding state, network login operates and BPDUs and 

user data flow in and out of the port. The forwarding state is the only STP state that 
allows network login and user data forwarding.

When RSTP is used with network login campus mode, autobind must be enabled on 

all VLANs that support RSTP and network login campus mode.

When RSTP is used with network login campus mode on a port, dynamic VLANs 

cannot be supported.

STP cannot be configured on the following ports:

A mirroring target port.