Dell C1048P Port Extender Networking Configuration Guide for the C9000 Series - Page 595

To view the current values for these interface parameters, use the show config command from INTERFACE mode. Configuring an EdgePort The EdgePort feature enables interfaces to begin forwarding traffic approximately 30 seconds sooner. In this mode, an interface forwards frames by default until it receives a BPDU that indicates that it should behave otherwise; it does not go through the Learning and Listening states. The bpduguard shutdown-on-violation option causes the interface hardware to be shut down when it receives a BPDU. When you implement only bpduguard, 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. EdgePort can cause loops if you enable it on an interface connected to a network. To enable EdgePort on an interface, use the following command. • Enable EdgePort on an interface. INTERFACE mode spanning-tree mstp edge-port [bpduguard | shutdown-on-violation] 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 disabled in the hardware. - You can clear the Error Disabled state with any of the following methods: * Use the shutdown command on the interface. * Disable the shutdown-on-violation command on the interface (using the no spanning-tree stp-id portfast [bpduguard | [shutdown-on-violation]] command). * Disable spanning tree on the interface (using the no spanning-tree command in INTERFACE mode). * Disabling global spanning tree (using the no spanning-tree command in CONFIGURATION mode). Example of Enabling an EdgePort on an Interface To verify that EdgePort is enabled, use the show config command from INTERFACE mode. Dell(conf-if-te-3/41)#spanning-tree mstp edge-port Dell(conf-if-te-3/41)#show config ! interface TengigabitEthernet 3/41 no ip address switchport spanning-tree mstp edge-port spanning-tree MSTI 1 priority 144 no shutdown Dell(conf-if-te-3/41)# Flush MAC Addresses after a Topology Change The system has an optimized MAC address flush mechanism for RSTP, MSTP, and PVST+ that flushes addresses only when necessary, which allows for faster convergence during topology changes. However, you may activate the flushing mechanism defined by 802.1Q-2003 using the tc-flush-standard command, which flushes MAC addresses after every topology change notification. Multiple Spanning Tree Protocol (MSTP) 595