User's Manual

Table Of Contents
Users Manual of GS-5220-8P2T2S Managed Switch
153
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.
4.3.5.2 STP System Configuration
This page allows you to configure STP system settings. The settings are used by all STP Bridge instances in the Switch. The
L2+ Managed PoE+ Switch support the following Spanning Tree protocols:
Compatiable -- Spanning Tree Protocol (STP):Provides a single path between end stations, avoiding and
eliminating loops.
Normal -- Rapid Spanning Tree Protocol (RSTP) : Detects and uses of network topologies that provide faster
spanning tree convergence, without creating forwarding loops.
ExtensionMultiple 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 System Configuration screen in Figure 4-3-5-4 appears.
Figure 4-3-5-4: STP Bridge Configuration Page Screenshot