Spanning Tree Configuration - ZyXEL Communications MGS3750-28F User Manual

Table 12 Spanning Tree Protocol Status Screen
LABEL
Hello Time (second)
Max Age (second)
Forwarding Delay
(second)
Topology Changed
Times
Port
Active
Pathcost
Priority
Role
State

6.3.1 Spanning Tree Configuration

Use the Spanning Tree Configuration screen to activate one of the STP modes on the Switch.
Click Configuration in the upper right corner of Spanning Tree Protocol Status screen.
The Switch supports Spanning Tree Protocol (STP), Rapid Spanning Tree Protocol (RSTP) and
Multiple Spanning Tree Protocol (MSTP) as defined in the following standards.
• IEEE 802.1D Spanning Tree Protocol
• IEEE 802.1w Rapid Spanning Tree Protocol
• IEEE 802.1s Multiple Spanning Tree Protocol
Chapter 6 Advanced Application Configurations
DESCRIPTION
This is the time interval (in seconds) at which the root switch transmits a configuration
message. The root bridge determines Hello Time, Max Age and Forwarding Delay.
This is the maximum time (in seconds) the Switch can wait without receiving a
configuration message before attempting to reconfigure.
This is the time (in seconds) the root switch will wait before changing states (that is,
listening to learning to forwarding).
Note: The listening state does not exist in RSTP.
This is the number of times the spanning tree has been reconfigured.
This field displays the number of the port on the Switch.
This field displays whether Global Spanning Tree is activated or not.
Path cost is the cost of transmitting a frame on to a LAN through that port. It is
recommended to assign this value according to the speed of the bridge. The slower
the media, the higher the cost.
Configure the priority for each port here.
Priority decides which port should be disabled when more than one port forms a loop
in a switch. Ports with a higher priority numeric value are disabled first. The allowed
range is between 0 and 255 and the default value is 128.
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.
If STP (Spanning Tree Protocol) is enabled, this field displays the STP state of the port.
If STP is disabled, this field displays FORWARDING if the link is up, otherwise, it
displays STOP.
When LACP (Link Aggregation Control Protocol), STP, and dot1x are in blocking state,
it displays Blocking.
MGS3750-28F User's Guide
28