Instruction Manual
66
Spanning Tree Protocol
The Spanning Tree Protocol 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 in your network to ensure that only
one route exists between any two stations on the network, and provide backup
links which automatically take over when a primary link goes down. The spanning
tree algorithms supported by this Managed Switch include these versions:
•
STP:
Spanning Tree Protocol (IEEE 802.1D).
•
RSTP:
Rapid Spanning Tree Protocol (IEEE 802.1w).
•
MSTP:
Multiple Spanning Tree Protocol (IEEE 802.1s).
The IEEE 802.1D Spanning Tree Protocol and IEEE 802.1w Rapid Spanning Tree
Protocol allow for the blocking of links between switches that form loops within
the network. When multiple links between switches are detected, a primary link
is established. Duplicated links are blocked from use and become standby links.
The protocol allows for the duplicate links to be used in the event of a failure of
the primary link. Once the Spanning Tree Protocol is configured and enabled,
primary links are established and duplicated links are blocked automatically.
The reactivation of the blocked links (at the time of a primary link failure) is also
accomplished automatically without operator intervention.
This automatic network reconfiguration provides maximum uptime to network
users. However, the concepts of the Spanning Tree Algorithm and protocol are a
complicated and complex subject and must be fully researched and understood.
It is possible to cause serious network performance degradation if the Spanning
Tree is incorrectly configured. Please read the following before making any
changes from the default values:
The Switch STP performs the following functions:
•
Creates a single spanning tree from any combination of switching or
bridging elements.
•
Creates multiple spanning trees – from any combination of ports contained
within a single switch, in user specified groups.
•
Automatically reconfigures the spanning tree to compensate for the failure,
addition, or removal of any element in the tree.
•
Reconfigures the spanning tree without operator intervention.
