Chapter 15 STP/RSTP Setup
66
15 STP/RSTP Setup
15.1 Overview
The Spanning Tree Algorithm can be used to detect and disable network loops and to provide backup links
between bridges. This allows the device to interact with other STP/RSTP-compliant switches or bridges in a
network to ensure that only one route exists between any two stations on the network and to provide backup
links which automatically take over when a primary link goes down.
In Figure 15-1, below, the forwarding port in IP 6610 #4 is blocked so that there can only be one path
between PC#1 and PC #2.
Root
Fwd.
Fwd.
Loop-IP 6610 #2
Root
Fwd.
Fwd.
Loop-IP 6610 #3
Loop-IP 6610 #1
ROOT
Fwd. Fwd.
PC #2
LAN1
PC #1
LAN1 WAN1
LAN1LAN1 WAN1
Root
Fwd.
Loop-IP 6610 #4
Traffic Path
Blocked
PC #2
Figure 15-1 Normal STP Link