ZyXEL Communications XS1920 Series, Руководство пользователя

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Chapter 13 Spanning Tree Protocol
XS1920 Series User’s Guide
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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.
Configuration
Name This field displays the configuration name for this MST region.
Revision Number This field displays the revision number for this MST region.
Configuration
Digest A configuration digest is generated from the VLAN-MSTI mapping information.
This field displays the 16-octet signature that is included in an MSTP BPDU. This field
displays the digest when MSTP is activated on the system.
Topology Changed
Times This is the number of times the spanning tree has been reconfigured.
Time Since Last
Change This is the time since the spanning tree was last reconfigured.
Instance: These fields display the MSTI to VLAN mapping. In other words, which VLANs run on each
spanning tree instance.
Instance This field displays the MSTI ID.
VLAN This field displays which VLANs are mapped to an MSTI.
MSTI Select the MST instance settings you want to view.
Bridge Root refers to the base of the MST instance. 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.
Internal Cost This is the path cost from the root port in this MST instance to the regional 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 MST instance.
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
ID This field displays the identifier of the designated bridge to which this port belongs when
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.
Table 57
Advanced Application > Spanning Tree Protocol > Status: MSTP (continued)
LABEL DESCRIPTION