Dell C1048P Port Extender Networking Configuration Guide for the C9000 Series - Page 811

interface hardware to be shut down when it receives a BPDU. When only bpduguard is implemented, although the interface is placed in an Error Disabled state when receiving the BPDU, the physical interface remains up and spanning-tree drops packets in the hardware after a BPDU violation. BPDUs are dropped in the software after receiving the BPDU violation. This feature is the same as PortFast mode in Spanning Tree. CAUTION: Configure EdgePort only on links connecting to an end station. If you enable EdgePort on an interface connected to a network, it can cause loops. Dell Networking OS Behavior: Regarding bpduguard shutdown-on-violation behavior: • If the interface to be shut down is a port channel, all the member ports are disabled in the hardware. • When you add a physical port to a port channel already in the Error Disable state, the new member port is also disabled in the hardware. • When you remove a physical port from a port channel in the Error Disable state, the error disabled state is cleared on this physical port (the physical port is enabled in the hardware). • The reset linecard command does not clear the Error Disabled state of the port or the hardware disabled state. The interface continues to be disables in the hardware. • You can clear the Error Disabled state with any of the following methods: - Perform an shutdown command on the interface. - Disable the shutdown-on-violation command on the interface (the no spanning-tree stp-id portfast [bpduguard | [shutdown-on-violation]] command). - Disable spanning tree on the interface (the no spanning-tree command in INTERFACE mode). - Disable global spanning tree (the no spanning-tree command in CONFIGURATION mode). To enable EdgePort on an interface, use the following command. • Enable EdgePort on an interface. INTERFACE mode spanning-tree rstp edge-port [bpduguard | shutdown-on-violation] Example of Verifying an EdgePort is Enabled on an Interface To verify that EdgePort is enabled on a port, use the show spanning-tree rstp command from EXEC privilege mode or the show config command from INTERFACE mode. NOTE: Dell Networking recommends using the show config command from INTERFACE mode. In the following example, the bold line indicates that the interface is in EdgePort mode. Dell(conf-if-te-2/0)#show config ! interface TenGigabitEthernet 2/0 no ip address switchport spanning-tree rstp edge-port shutdown Configuring Fast Hellos for Link State Detection Use RSTP fast hellos to achieve sub-second link-down detection so that convergence is triggered faster. The standard RSTP link-state detection mechanism does not offer the same low link-state detection speed. RSTP fast hellos decrease the hello interval to the order of milliseconds and all timers derived from the hello timer are adjusted accordingly. This feature does not inter-operate with other vendors, and is available only for RSTP. • Configure a hello time on the order of milliseconds. PROTOCOL RSTP mode hello-time milli-second interval The range is from 50 to 950 milliseconds. Rapid Spanning Tree Protocol (RSTP) 811