Configuring Spanning Tree Link Type

If a port is configured as point-to-point link and its port role is designated, then IS5Com RSTP negotiates a rapid transition to forwarding with the other port by using proposal-handshake agreement mechanism to ensure that the topology is loop free. By default, if the interface is full-duplex, it is considered to have a point to point connection. If the interface is half duplex, then it is considered to have a shared connection. This default setting of link type can be overridden to enable rapid transition to forwarding state.

Execute the following commands in the Switch C.

Type the following:

Enter the Global Configuration Mode in ISS1.

iS5comm# configure terminal

Specify the interface for which the path cost is to be configured

iS5comm(config)# interface gigabitethernet 0/1

Valid interfaces include physical interfaces and port-channel logical interfaces (port-channel port-channel-number).

Configure link type of interface as point-to-point.

iS5comm(config-if) # spanning-tree link-type point-to-point

Return to the Privileged EXEC mode.

iS5comm(config)#end

View the spanning tree properties by executing the following show command.

iS5comm# show spanning-tree detail

Spanning tree Protocol Enabled.

MST00 is executing the mstp compatible Multiple Spanning Tree Protocol

Bridge Identifier has Priority 32768, Address 00:01:02:03:04:01

Configured  Max age 20 sec 0 cs,  Forward delay 15 sec 0 cs

Configured Hello Time 2 sec 0 cs

We are root of the spanning tree

Current Root has priority 32768, address  00:01:02:03:04:01cost of root path is 0

Number of Topology Changes 1, Time since topology Change 37 seconds ago

Transmit Hold-Count 3

Root Times : Max age 20 sec 0 cs     Forward delay

15 sec 0 cs

Port 1 [Gi0/1] of MST00 is Designated, Forwarding

Gi0/1 is operating in the MSTP Mode

Port path cost  200000, Port priority  128,

Port Identifier  128.1. Port HelloTime  2 sec 0 cs,

Timers:Hello - 0,Forward Delay - 0,Topology Change - 2

Designated root has priority 32768, address 00:01:02:03:04:01

Designated Bridge has priority 32768, address 00:01:02:03:04:01

Designated Port Id is 128.1, Designated pathcost is 0

Operational Forward delay 15 sec 0 cs, Max age 20 sec 0 cs

Number of Transitions to forwarding State : 1

PortFast is disabled

Link type is point to Point

BPDUs : sent 35, received 53

Restricted Role is disabled.

Restricted TCN is disabled.

Execute the no spanning-tree link-type Interface Configuration mode command to set the default link type for an Interface.

iS5comm(config-if) # no spanning-tree link-type