Dell Force10 Z9000 FTOS Command Line Reference Guide for the Z9000 System FTOS - Page 1422

Defaults Command Modes Command History Usage Information portfast [bpduguard [shutdown-onviol ation]] priority priority Enter the keyword portfast to enable Portfast to move the interface into Forwarding mode immediately after the root fails. Enter the optional keyword bpduguard to disable the port when it receives a BPDU. Enter the optional keyword shutdown-on-violation to hardware disable an interface when a BPDU is received and the port is disabled. Enter keyword priority followed by a number as the priority. The range is zero (0) to 15. The default is 8. cost = depends on the interface type; priority = 8 INTERFACE Version 8.3.11.1 Version 8.3.10.1 Version 8.4.2.1 Version 8.3.7.0 Version 8.2.1.0 Version 7.7.1.0 Version 7.5.1.0 Version 6.2.1.1 Introduced on the Z9000. Introduced the loopguard and rootguard options on the S4810. Introduced the loopguard and rootguard options on the ESeries TeraScale, C-Series, and S-Series. Introduced on the S4810. Introduced the shutdown-on-violation option. Introduced on the S-Series. Introduced on the C-Series. Introduced on the E-Series. If you enable portfast bpduguard on an interface and the interface receives a BPDU, the software disables the interface and sends a message stating that fact. The port is in ERR_DISABLE mode, yet appears in the show interface commands as enabled. If you do not enable shutdown-on-violation, BPDUs still are sent to the RPM CPU. STP loop guard and root guard are supported on a port or port-channel enabled in any Spanning Tree mode: Spanning Tree Protocol (STP), Rapid Spanning Tree Protocol (RSTP), Multiple Spanning Tree Protocol (MSTP), and Per-VLAN Spanning Tree Plus (PVST+). Root guard is supported on any STP-enabled port or port-channel except when used as a stacking port. When enabled on a port, root guard applies to all VLANs configured on the port. STP 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. Do not enable Portfast BPDU guard and loop guard at the same time on a port. Enabling both features may result 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 ErrDisabled 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 LoopInconsistent Blocking state and no traffic is forwarded on the port. 1422