STP Status

Use the STP Status page to view information about VLANs that have Spanning Tree Protocol (STP) enabled. STP is a Link Layer network protocol that ensures a loop-free topology for any bridged LAN. No information is displayed for VLANs without STP enabled.

At the top of the page, use the Check the STP status in this VLAN list to choose a VLAN.

STP Status > Global Status

Field	Description
Bridge ID	An unique ID for the other devices on the network to identify this device.
Root Bridge ID	The bridge ID of the root bridge.
Root Port	The Port ID of the root port. The root port is the port with the lowest path cost to the root bridge. The root bridge does not have a root port.
Root Path Cost	The cost of the shortest path from the security appliance to the root bridge. The value 0 indicates that this security appliance is the root bridge.

Interface Status Table

Field	Description
Interface	The interface name.
Port Role	The role assigned to this port • Root port: The port with the lowest path cost to the root bridge. • Designated port: The port with the lowest path cost on a LAN segment. The LAN segment will use the designated port to reach the root bridge. • Blocked port: The port that is neither a root port nor a designated port.
Path Cost	The cost of the path to root bridge through this port.
Priority	Priority of the port.
Port State	The state of the port: • Disabled: This port is disabled. It will not transmit or receive any traffic. • Blocking: This port is enabled but blocked by STP. It will not transmit or receive any traffic. • Listening: This port will receive and process STP bridge protocol data units (BPDUs), but will not forward any data traffic. • Learning: This port will start to learn MAC addresses from the received packets. It will also receive and process STP BPDUs, but will not forward any data traffic. • Forwarding: This port will forward data traffic, process BPDUs and learn MAC address.
Designated Bridge ID	The ID of the designated bridge of the LAN segment. The designated bridge is used by all the other devices on the LAN segment to reach the root bridge.
Designated Port ID	The ID of the designated port of the LAN segment. The designated port is the port used by all the other devices on the LAN segment to reach the root bridge.
Designated Cost	The path cost to the designated bridge of the LAN segment.