Cisco SG220-26 - Page 159

Spanning Tree Protocol
Configuring Multiple Spanning Tree
Cisco 220 Series Smart Switches Administration Guide Release 1.1.0.x 157
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The MSTP settings for the interfaces on the instance are displayed.
STEP 3 Select an interface, and click Edit.
STEP 4 Enter the following information:
• Instance ID—Select the MSTP instance to be configured.
• Interface—Select the port or LAG to be configured.
• Path Cost—Select User Defined to set the port contribution to the root path
cost, or select Use Default to use the default value. The root path cost is the
cost of the switch to the Root Bridge of the specified MSTP instance.
• Priority—Enter the port priority for the selected port and MSTP instance.
• Port State—Displays the MSTP status of the port. The values are:
- Disabled—MSTP is currently disabled.
- Blocking—The port on this instance is currently blocked, and cannot
forward traffic (with the exception of BPDU data) or learn MAC
addresses.
- Learning—The port on this instance is in Learning mode, and cannot
forward traffic. But it can learn new MAC addresses.
- Forwarding—The port on this instance is in Forwarding mode, and can
forward traffic and learn new MAC addresses.
• Port Role—Displays the port role per instance, assigned by the MSTP
algorithm to provide STP paths:
-
Master —A Master port provides connectivity from an MSTP region to the
outlying CIST root.
- Root—Forwarding packets through this port provides the lowest cost
path to forward packets to the root device.
- Designated—The port through which the bridge is connected to the LAN
that provides the lowest root path cost from the LAN to the Root Bridge
for the MST instance.
- Alternate—The port provides an alternate path to the root device from
the root interface.