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3
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4 Spanning Tree
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4.1 Bride
Settings
The Spanning Tree Protocol (STP) can be used to detect and disable network loops,
and to provide backup links between switches, bridges, or routers. This allows the
switch to interact with other bridging devices (e.g. an STP
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compliant switch, bridge,
or router) in your network to ensure that only one route exists between any two
stations on the network. It also provides backup links, which automatically take over
when the primary link goes down.
STP
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STP uses a distributed algorithm to select a bridging device (STP
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compliant
switch, bridge, or router) that serves as the root of the spanning tree network. It
selects a root port on each bridging device (except for the root device), which incurs
the lowest path cost when forwarding a packet from that device to the root device.
Then, it selects a designated bridging device from each LAN, which incurs the lowest
path cost when forwarding a packet from that LAN to the root device. All ports
connected to the designated bridging devices are assigned as designated ports. After
determining the lowest cost spanning tree, it enables all root ports and designated
ports, and disables all other ports. Therefore, the
network packets are only
forwarded between root ports and designated ports to eliminate any possible
network loops.
Once a stable network topology had been established, all bridges listen for Hello
BPDUs (Bridge Protocol Data Units) transmitted from the Root Bridge. If a bridge
does not get a Hello BPDU after a predefined interval (Maximum Age), the bridge
assumes that the link to the Root Bridge is down. This bridge will then initiate
negotiations with other bridges to reconfigure the network to reestablish a valid
network topology.
The section describes how to configure the Spanning Tree Bridge and STP System
settings. It allows you to configure STP System settings used by all STP Bridge
instance in the Switch Stack.
Web Interface
To configure the Spanning Tree Bridge Settings parameters in the web interface:
1.
Click Configuration, Spanning Tree, Bridge Settings.
2.
Scroll to select the parameters and write down available value of
parameters in blank field in Basic Settings.
3.
Evoke to enable or disable the parameters and write down available value
of parameters in blank field in Advanced settings.
4.
Click “Save” to save the setting.
5.
If you want to cancel the setting, click the reset button to revert back to
previously saved values.
