Dell PowerSwitch S4128F-ON EMC SmartFabric OS10 User Guide Release 10.5.1 - Page 505

● The interface and all member ports are disabled in the hardware. ● When the port is added to the port channel that is in the Error Disable state, the new member port is disabled in the hardware. ● When the port is removed from the port channel that is in the Error Disable state, the system clears the Error_Disabled state on the physical port and enables it in the hardware. To clear the Error Disabled state: ● Use the shutdown command on the interface. ● Use the spanning-tree bpduguard disable command to disable the BPDU guard on the interface. ● Use the spanning-tree disable command to disable STP on the interface. 3. Set the guard types to avoid loops in INTERFACE mode. spanning-tree guard {loop | root | none} ● loop - Set the guard type to loop. ● root - Set the guard type to root. ● none - Set the guard type to none. Port enabled with loop guard conditions ● Loop guard is supported on any STP-enabled port or port-channel interface. ● You cannot enable root guard and loop guard at the same time on an STP port. The loop guard configuration overwrites an existing root guard configuration and vice versa. ● Enabling BPDU guard and loop guard at the same time on a port results in a port that remains in blocking state and prevents traffic from flowing through it. For example, when you configure both Portfast BPDU guard and loop guard: ○ If a BPDU is received from a remote device, BPDU guard places the port in the Err-Disabled Blocking state and no traffic forwards on the port. ○ If no BPDU is received from a remote device which was sending BPDUs, loop guard places the port in the LoopInconsistent Blocking state and no traffic forwards on the port. ● When used in a Rapid-PVST network, STP loop guard performs per-port or per port-channel at a VLAN level. If no BPDUs are received on a port-channel interface, the port or port-channel transitions to a Loop-Inconsistent or Blocking state only for this VLAN. BPDU filter os10(conf-if-eth1/1/7)# spanning-tree bpdufilter enable os10(conf-if-eth1/1/7)# do show spanning-tree interface ethernet 1/1/7 ethernet1/1/7 of vlan 1 is Designated Forwarding Edge port: No (default) Link type: point-to-point (auto) Boundary: No, Bpdu-filter: Enable, Bpdu-Guard: Disable, Shutdown-on-Bpdu-Guard- violation: No Root-Guard: Disable, Loop-Guard: Disable Bpdus (MRecords) Sent: 6, Received: 6410 Interface Designated Name PortID Prio Cost Sts Cost Bridge ID PortID -- ethernet1/1/7 128.56 128 500 FWD 500 32769 90b1.1cf4.a625 128.56 BPDU guard os10(config)# interface ethernet 1/1/7 os10(conf-if-eth1/1/7)# spanning-tree bpduguard enable os10(conf-if-eth1/1/7)# do show spanning-tree interface ethernet 1/1/7 ethernet1/1/7 of vlan 1 is Designated Forwarding Edge port: No (default) Link type: point-to-point (auto) Boundary: No, Bpdu-filter: Enable, Bpdu-Guard: Enable, Shutdown-on-Bpdu-Guard-violation: Yes Root-Guard: Disable, Loop-Guard: Disable Bpdus (MRecords) Sent: 6, Received: 6410 Interface Designated Name PortID Prio Cost Sts Cost Bridge ID PortID ---- Layer 2 505