Cisco SF352-08MP - Page 336

Spanning Tree
MSTP Interface Settings
256 Cisco 350, 350X and 550X Series Managed Switches, Firmware Release 2.4, ver 0.4
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• Path Cost—Enter the port contribution to the root path cost in the User Defined
textbox or select Use Default to use the default value.
• Port State—Displays the MSTP status of the specific port on a specific MST instance.
The parameters are defined as:
- Disabled—STP is currently disabled.
- Discarding—The port on this instance is currently discarding/blocked, and cannot
forward traffic (with the exception of BPDU data) or learn MAC addresses.
- Listening—The port on this instance is in Listening mode. The port cannot forward
traffic, and cannot learn MAC addresses.
- Learning—The port on this instance is in Learning mode. The port cannot forward
traffic, but it can learn new MAC addresses.
- Forwarding—The port on this instance is in Forwarding mode. The port can
forward traffic and learn new MAC addresses.
- Boundary—The port on this instance is a boundary port. It inherits its state from
instance 0 and can be viewed on the STP Interface Settings page.
• Port Role—Displays the port or LAG role, per port or LAG per instance, assigned by
the MSTP algorithm to provide STP paths:
- Root—Forwarding packets through this interface provides the lowest cost path for
forwarding packets to the root device.
- Designated Port—The interface through which the bridge is connected to the LAN,
which provides the lowest root path cost from the LAN to the Root Bridge for the
MST instance.
- Alternate—The interface provides an alternate path to the Root Bridge from the root
port.
- Backup—The interface provides a backup path to the designated port path toward
the Spanning Tree leaves. Backup ports occur when two ports are connected in a
loop by a point-to-point link. Backup ports also occur when a LAN has two or more
established connections to a shared segment.
- Disabled—The interface does not participate in the Spanning Tree.
- Boundary—The port on this instance is a boundary port. It inherits its state from
instance 0 and can be viewed on the STP Interface Settings page.
• Mode—Displays the current interface Spanning Tree mode.
- If the link partner is using MSTP or RSTP, the displayed port mode is RSTP.