Cisco Cisco SG200-26P 26-port Gigabit PoE Smart Switch Manuel De Maintenance
Spanning Tree
Configuring STP Status and Global Settings
Cisco Small Business SF200E Series Advanced Smart Switch
127
6
BPDU exchanges also facilitate the election of a root bridge and root port for the
network. The root bridge provides a reference point that each other bridge uses to
calculate a lowest-cost path by summing the cost of the ports in each path and
choosing the one with the lowest total. The port that connects a bridge to the
lowest-cost path is called the bridge’s root port.
network. The root bridge provides a reference point that each other bridge uses to
calculate a lowest-cost path by summing the cost of the ports in each path and
choosing the one with the lowest total. The port that connects a bridge to the
lowest-cost path is called the bridge’s root port.
When the root bridge is selected and each root port is established, each network
segment can then determine which bridge provides the lowest cost path to the
root port. The port that provides this path is named the designated port for the
network segment. Spanning tree disables other ports for that network segment or
designates them as alternate or backup ports.
segment can then determine which bridge provides the lowest cost path to the
root port. The port that provides this path is named the designated port for the
network segment. Spanning tree disables other ports for that network segment or
designates them as alternate or backup ports.
Supported spanning tree versions include Common Spanning Tree (CST), Rapid
STP (RSTP), and Multiple STP (MSTP).
STP (RSTP), and Multiple STP (MSTP).
•
CST (IEEE 802.1D) is the original protocol version that provides a single path
between end stations, avoiding and eliminating loops.
between end stations, avoiding and eliminating loops.
•
RSTP (IEEE 802.1D-2004 or IEEE 802.1w) provides protocol enhancements
that enable a network to more quickly achieve an optimal STP topology.
Spanning tree is enabled by default and set to be RSTP.
that enable a network to more quickly achieve an optimal STP topology.
Spanning tree is enabled by default and set to be RSTP.
•
MSTP (IEEE 802.1Q-2005 or IEEE 802.1s) supports multiple instances of
Spanning Tree to efficiently channel VLAN traffic over different interfaces.
Each instance of the Spanning Tree behaves in the manner specified in
Rapid Spanning Tree (RSTP), with some modifications. An MSTP bridge can
be configured to behave entirely as a RSTP bridge or a STP bridge.
Spanning Tree to efficiently channel VLAN traffic over different interfaces.
Each instance of the Spanning Tree behaves in the manner specified in
Rapid Spanning Tree (RSTP), with some modifications. An MSTP bridge can
be configured to behave entirely as a RSTP bridge or a STP bridge.
Configuring STP Status and Global Settings
You can use the STP Status & Global Settings page to enable STP, select the STP
mode of operation, and configure bridge priority settings. You can also view status
information about the STP topology. To display this page, click Spanning Tree >
STP Status & Global Settings in the navigation window.
mode of operation, and configure bridge priority settings. You can also view status
information about the STP topology. To display this page, click Spanning Tree >
STP Status & Global Settings in the navigation window.
This page enables you to configure global settings and bridge settings, and
displays information about the designated root.
displays information about the designated root.