Dell Force10 S4810P Reference Manual page 1550

portfast
[bpduguard
[shutdown-on-
viol ation]]
priority
Defaults cost = depends on the interface type; priority = 8
Command Modes INTERFACE
Command History
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
Usage
If you enable portfast bpduguard on an interface and the interface receives a BPDU,
Information
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:
1550
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.
priority Enter keyword priority followed by a number as the priority. The
range is zero (0) to 15. The default is 8.
Introduced on the Z9000.
Introduced the loopguard and rootguard options on the S4810.
Introduced the loopguard and rootguard options on the E-
Series 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 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.