A - 26
FORE Systems ES-2810 Ethernet Switch User’s Manual
Concepts in Switching
A.7.2.10 Configuration BPDU Messages
To establish the stable paths, each switch sends Configuration BPDU Frames to its neighbor-
ing switches. These Configuration BPDU messages contain information about the spanning
tree topology. The contents of these frames only changes when the bridged network topology
changes or has not been established.
A.7.2.11 Configuration BPDU Message Propagation
When a bridged network is in a stable condition, switches continue to send Configuration
BPDU Frames to its neighboring switches at regular intervals. Configuration BPDU Frames
are transmitted down the spanning tree from Designated Ports to Root Ports. If a Configura-
tion BPDU is not received by the Root Port on a switch in a predefined time interval (for exam-
ple, because a switch along the path has dropped out), the port enters the Listening State to
redetermine its stable path.
A.7.2.12 MAC Address Ageing
MAC address ageing is overruled by changes in the Spanning Tree. When the Spanning Tree is
bridging and blocking, the topology of the network can change. This means the MAC
addresses are changing and the Spanning Tree overrides the set MAC address ageing value.
To Next Page
Loading...