Dell PowerEdge FN I/O Module Command Line Reference Guide 9.10(0.0)

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spanning-tree mstp

Configures a Layer 2 MSTP interface as an edge port with (optionally) a bridge protocol data unit (BPDU) guard, or enables the root guard or loop guard feature on the interface.

Syntax

spanning-tree mstp {edge-port [bpduguard [shutdown-on-violation]] | bpdufilter| rootguard}

Parameters

edge-port	Enter the keywords `edge-port` to configure the interface as a multiple spanning tree edge port.
bpduguard	(OPTIONAL) Enter the keyword `portfast` to enable Portfast to move the interface into forwarding mode immediately after the root fails. Enter the keyword `bpduguard` to disable the port when it receives a BPDU.
bpdufilter	(OPTIONAL) Enter the keyword `edgeport` to enable edge port configuration to move the interface into forwarding mode immediately after the root fails. Enter the keyword `bpdufilter` to stop sending and receiving BPDUs on the port-fast enabled ports.
shutdown-on-violation	(OPTIONAL) Enter the keywords `shutdown-on-violation` to hardware disable an interface when a BPDU is received and the port is disabled.
rootguard	Enter the keyword `rootguard` to enable root guard on an MSTP port or port-channel interface.

Command Modes

INTERFACE

Supported Modes

Full–Switch

Command History

Version	Description
9.9(0.0)	Introduced on the FN IOM.
8.3.16.1	Introduced on the MXL 10/40GbE Switch IO Module.

Usage Information

On an MSTP switch, a port configured as an edge port immediately transitions 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 spanning-tree portfast enabled.

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 an MSTP network, if root guard blocks a boundary port in the CIST, the port is also blocked in all other MST instances.

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.