spanning-tree link-type
spanning-tree link-type
Use the spanning-tree link-type interface configuration command on a network node interface (NNI)
or enhanced network interface (ENI) with STP enabled to override the default link-type setting, which
is determined by the duplex mode of the STP port, and to enable rapid spanning-tree transitions to the
forwarding state. Use the no form of this command to return to the default setting.
Syntax Description
point-to-point
shared
Defaults
The switch derives the link type of an interface from the duplex mode. A full-duplex interface is
considered a point-to-point link, and a half-duplex interface is considered a shared link.
Command Modes
Interface configuration
Command History
Release
12.2(25)EX
Usage Guidelines
Spanning Tree Protocol (STP) is not supported on user network interfaces (UNIs). You can configure
spanning-tree link type only on NNIs or on ENIs on which STP has been enabled. To set a port as an
NNI or ENI, enter the port-type {eni | nni} interface configuration command. To enable STP on an ENI,
enter the spanning-tree interface configuration command.
You can override the default setting of the link type by using the spanning-tree link-type command. For
example, a half-duplex link can be physically connected point-to-point to a single interface on a remote
switch running the Multiple Spanning Tree Protocol (MSTP) or the rapid per-VLAN spanning-tree plus
(rapid-PVST+) protocol and be enabled for rapid transitions.
Examples
This example shows how to specify the link type as shared (regardless of the duplex setting) and to
prevent rapid transitions to the forwarding state:
Switch(config-if)# spanning-tree link-type shared
You can verify your setting by entering the show spanning-tree mst interface interface-id or the show
spanning-tree interface interface-id privileged EXEC command.
Cisco ME 3400 Ethernet Access Switch Command Reference
2-566
spanning-tree link-type {point-to-point | shared}
no spanning-tree link-type
Specify that the link type of an STP port is point-to-point.
Specify that the link type of an STP port is shared.
Modification
This command was introduced.
Chapter 2 Cisco ME 3400 Ethernet Access Switch Cisco IOS Commands
OL-9640-07