ZyXEL Communications XGS3700-48 User Manual page 146

The following table describes the labels in this screen.
Table 61 Advanced Application > Spanning Tree Protocol > Status: MRSTP
LABEL DESCRIPTION
Configuration Click Configuration to specify which STP mode you want to activate. Click MRSTP to
edit MRSTP settings on the Switch.
Tree Select which STP tree configuration you want to view.
Bridge Root refers to the base of the spanning tree (the root bridge). Our Bridge is this Switch.
This Switch may also be the root bridge.
Bridge ID This is the unique identifier for this bridge, consisting of bridge priority plus MAC address.
This ID is the same for Root and Our Bridge if the Switch is the root switch.
Hello Time This is the time interval (in seconds) at which the root switch transmits a configuration
(second) message. The root bridge determines Hello Time, Max Age and Forwarding Delay.
Max Age (second) This is the maximum time (in seconds) a switch can wait without receiving a
configuration message before attempting to reconfigure.
Forwarding Delay This is the time (in seconds) the root switch will wait before changing states (that is,
(second) listening to learning to forwarding).
Note: The listening state does not exist in RSTP.
Cost to Bridge This is the path cost from the root port on this Switch to the root switch.
Port ID This is the priority and number of the port on the Switch through which this Switch must
communicate with the root of the Spanning Tree.
Topology Changed This is the number of times the spanning tree has been reconfigured.
Times
Time Since Last This is the time since the spanning tree was last reconfigured.
Change
Port This field displays the number of the port on the Switch.
Port State This field displays the port state in STP.
• Discarding - The port does not forward/process received frames or learn MAC
addresses, but still listens for BPDUs.
• Learning - The port learns MAC addresses and processes BPDUs, but does not
forward frames yet.
• Forwarding - The port is operating normally. It learns MAC addresses, processes
BPDUs and forwards received frames.
Port Role This field displays the role of the port in STP.
• Root - A forwarding port on a non-root bridge, which has the lowest path cost and is
the best port from the non-root bridge to the root bridge. A root bridge does not have
a root port.
• Designated - A forwarding port on the designated bridge for each connected LAN
segment. A designated bridge has the lowest path cost to the root bridge among the
bridges connected to the LAN segment. All the ports on a root bridge (root switch) are
designated ports.
• Alternate - A blocked port, which has a best alternate path to the root bridge. This
path is different from using the root port. The port moves to the forwarding state
when the designated port for the LAN segment fails.
• Backup - A blocked port, which has a backup/redundant path to a LAN segment
where a designated port is already connected when a switch has two links to the
same LAN segment.
• Disabled - Not strictly part of STP. The port can be disabled manually.
Designated Bridge This field displays the identifier of the designated bridge to which this port belongs when
ID the port is a designated port. Otherwise, it displays the identifier of the designated bridge
for the LAN segment to which this port is connected.
Designated Port This field displays the priority and number of the bridge port (on the designated bridge),
ID through which the designated bridge transmits the stored configuration messages.
Chapter 11 Spanning Tree Protocol
GS3700/XGS3700 Series User's Guide
146