PLANET LRP-822CS - Manual (Page 144)

User’s Manual of LRP-822CS
144
The switch with the lowest Bridge ID (switch C) was elected the root bridge, and the ports were selected to give a high port cost
between switches B and C. The two (optional) Gigabit ports (default port cost = 20,000) on switch A are connected to one
(optional) Gigabit port on both switch B and C. The redundant link between switch B and C is deliberately chosen as a 100
Mbps Fast Ethernet link (default port cost = 200,000). Gigabit ports could be used, but the port cost should be increased from
the default to ensure that the link between switch B and switch C is the blocked link.
This section has the following items:
 STP Global Setting Configures STP system settings
 STP Port Setting Configures per port STP setting
 CIST Instance Setting Configures system configuration
 CIST Port Setting Configures CIST port setting
 MST Instance Setting Configures each MST instance setting
 MST Port Setting Configures per port MST setting
 STP Statistics Displays the STP statistics
4.6.2 STP Global Settings
This page allows you to configure STP system settings. The settings are used by all STP Bridge instances in the Switch. The
LRP Managed Switch support the following Spanning Tree Protocols:
‧ Compatible -- Spanning Tree Protocol (STP): Provides a single path between end stations, avoiding and
eliminating loops.
‧
Normal -- Rapid Spanning Tree Protocol (RSTP): Detects and uses network topologies that provide faster
spanning tree convergence, without creating forwarding loops.
‧ Extension – Multiple Spanning Tree Protocol (MSTP): Defines an extension to RSTP to further develop the
usefulness of virtual LANs (VLANs). This "Per-VLAN" Multiple Spanning Tree Protocol configures a separate
Spanning Tree for each VLAN group and blocks all but one of the possible alternate paths within each Spanning
Tree.
The STP Global Settings screens in Figure 4-6-4 & Figure 4-6-5 appear.