Dell Force10 S4820T FTOS Command Reference Guide - Page 1201
port-channel transitions to a loop-inconsistent blocking state only for this VLAN.
View all Dell Force10 S4820T manuals
Add to My Manuals
Save this manual to your list of manuals |
Page 1201 highlights
Usage Information The BPDU guard option prevents the port from participating in an active STP topology in case a BPDU appears on a port unintentionally, or is misconfigured, or is subject to a DOS attack. This option places the port into an error disable state if a BPDU appears, and a message is logged so that the administrator can take corrective action. Note: A port configured as an edge port, on a PVST switch, will immediately transition to the forwarding state. Only ports connected to end-hosts should be configured as an edge port. Consider an edge port similar to a port with a spanning-tree portfast enabled. Example Related Commands If shutdown-on-violation is not enabled, BPDUs will still be sent to the RPM CPU. Root guard and loop guard cannot be enabled at the same time on a port. For example, if you configure loop guard on a port on which root guard is already configured, the following error message is displayed: % Error: RootGuard is configured. Cannot configure LoopGuard. When used in a PVST+ network, loop guard is performed per-port or per-port channel at a VLAN level. If no BPDUs are received on a VLAN interface, the port or port-channel transitions to a loop-inconsistent (blocking) state only for this VLAN. Enabling Portfast BPDU guard and loop guard at the same time on a port results in a port that remains in a blocking state and prevents traffic from flowing through it. For example, when Portfast BPDU guard and loop guard are both configured: • If a BPDU is received from a remote device, BPDU guard places the port in an err-disabled blocking state and no traffic is forwarded on the port. • If no BPDU is received from a remote device, loop guard places the port in a loop-inconsistent blocking state and no traffic is forwarded on the port. FTOS(conf-if-gi-1/1)#spanning-tree pvst vlan 3 cost 18000 FTOS(conf-if-gi-1/1)#end FTOS(conf-if-gi-1/1)#show config ! interface GigabitEthernet 1/1 no ip address switchport spanning-tree pvst vlan 3 cost 18000 no shutdown FTOS(conf-if-gi-1/1)#end FTOS# show spanning-tree pvst View PVST+ configuration Per-VLAN Spanning Tree Plus (PVST+) | 1201