Configuring Spanning Tree
Configuring Rapid Spanning Tree
Page 139
Configuring Rapid Spanning Tree
While Classic STP prevents Layer 2 forwarding loops in a general network topology, convergence can take
between 30-60 seconds. This time may delay detecting possible loops and propagating status topology changes.
Rapid Spanning Tree Protocol
(RSTP) detects and uses network topologies that allow a faster STP convergence
without creating forwarding loops.
To define RSTP on the device:
1.
Click
Layer 2 > RSTP
. The
RSTP Page
opens:
Figure 93: RSTP Page
The
RSTP Page
contains the following fields:
•
Select the interfaces displayed in the table.
–
Ports of Unit
— Specifies the port and stacking member for which the RSTP settings are displayed.
–
Trunks
— Specifies the trunk for which the RSTP settings are displayed.
•
Interface
— Displays the port or trunk on which Rapid STP is enabled.
•
Role
— Displays the port role assigned by the STP algorithm to provide to STP paths. The possible field
values are:
–
Root
— Provides the lowest cost path to forward packets to the root switch.
–
Designated
— The port or trunk through which the designated switch is attached to the LAN.
–
Alternate
— Provides an alternate path to the root switch from the root interface.
–
Backup
— Provides a backup path to the designated port path toward the Spanning Tree leaves. Backup
ports occur only when two ports are connected in a loop by a point-to-point link, or when a LAN has two
or more connections to a shared segment.
–
Disabled
— The port is not participating in the Spanning Tree.
