Configuring per-port spanning tree
Syntax:
spanning-tree port-list admin-edge-portno spanning-tree port-list admin-edge-portEnables
admin-edge-port on ports connected to end nodes. During spanning tree establishment, ports with
admin-edge-port enabled transition immediately to the forwarding state. If a bridge or switch is detected on the segment, the port automatically operates as non-edge, not enabled.
If
admin-edge-port is disabled on a port and
auto-edge-port has not been disabled, the
auto-edge-port setting controls the behavior of the port.
Default: No - disabled
The no form of the command disables edge-port operation on the specified ports.
Syntax:
spanning tree port-list auto-edge-portno spanning tree port-list auto-edge-portEnables or disables the automatic identification of edge ports. The port will look for BPDUs for 3 seconds. If there are none, it begins forwarding packets. If
admin-edge-port is enabled for a port, the setting for auto-edge-port is ignored whether set to yes or no. If
admin-edge-port is set to No, and
auto-edge- port has not been disabled (set to No), then the auto-edge-port setting controls the behavior of the port.
Default: Yes - enabled
The
no form of the command disables
auto-edge-port operation on the specified ports.
Syntax:
no spanning tree port-list bpdu-filterEnables or disables BPDU filtering on the specified port(s). The
bpdu-filter option forces a port to always stay in the forwarding state and be excluded from standard STP operation.
Default: Disabled
Syntax:
Enables or disables BPDU protection on the specified port(s).
Syntax:
spanning tree port-list point-to-point-mac [true | false | auto]Informs the switch of the type of device to which a specific port connects.
true(default)Indicates a point-to-point link to a device such as a switch, bridge, or end-node.
falseIndicates a connection to a hub (which is a shared LAN segment).
autoCauses the switch to set Force-False on the port if it is not running at full duplex. (Connections to hubs are half-duplex.)
Syntax:
spanning tree port-list root-guardThis feature is available in RPVST+ only. When a port is enabled as
root-guard, it cannot be selected as the root port even if it receives superior STP BPDUs. The port is assigned an “alternate” port role and enters a blocking state if it receives superior STP BPDUs. (A superior BPDU contains “better” information on the root bridge and path cost to the root bridge, which would normally replace the current root bridge selection.)
The superior BPDUs received on a port enabled as
root-guard are ignored. All other BPDUs are accepted and the external devices may belong to the spanning tree as long as they do not claim to be the Root device. Use the following command on RPVST+ switch ports that are connected to devices located in other administrative network domains to ensure the stability of the core RPVST+ network topology so that undesired or damaging influences external to the network do not enter.
Default: Disabled.
Syntax:
spanning-tree port-list tcn-guardWhen
tcn-guard is enabled for a port, it causes the port to stop processing or propagating received topology change notifications and topology changes to other ports.
Default: Disabled.