Netgear XCM8810 - 8800 SERIES 10-SLOT CHASSIS SWITCH ユーザーズマニュアル

port_list

—Specifies one or more ports or slots and ports.

Restricted role is disabled by default. If set, it can cause a lack of spanning tree 

connectivity. A network administrator enables restricted role to prevent external 
bridges from influencing the spanning tree active topology.

BPDU Restrict on Edge Safeguard

BPDU restrict causes a port on which this feature is configured to be disabled as soon as an 
STP BPDU is received on that port thus allowing you to enforce the STP domain borders and 
keep the active topology predictable. 

 shows a BPDU restrict example.

In this figure, loops on the LAN access switches are not prevented since the ports towards 
the distribution switches are not running STP but Software Redundant Ports (SRP). 
Currently, XCM8800 software cannot run STP on ports that are configured for SRP. STP on 
the access switch is unaware of the alternate path and therefore cannot prevent the loop that 
exists across the switches. Configuring a port as an edge mode port alone cannot prevent the 
loop between the switches because edge ports never send BPDUs. The edge safeguard 
feature is not able to prevent the loops because STP does not have the information about the 
alternate path. 

To prevent the loops across the switches, the edge safeguard feature can be configured with 
the BPDU restrict function. When running in BPDU restrict mode, edge safeguard ports send 
STP BPDUs at a rate of 1 every 2 seconds. The port is disabled as soon as an STP BPDU is 
received on the BPDU restrict port, thereby preventing the loop. Flexibility is provided with an 
option to re-enable the port after a user specified time period. If a user enables a port while 
STP has disabled it, the port is operationally enabled; STP is notified and then stops any 
recovery timeout that has started. 

Distribution

Access

BPDU
Restrict Enabled
Edge Port

BPDU

Restrict Enabled

Edge Port

Switch C

Switch D

SRP

Loop

SRP

Switch A

Switch B