Compex Systems SGX3226 - Manual (Page 51)

Chapter 7 Advanced Configuration for Compex SGX3226
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Chapter 7 Advanced Configuration for Compex SGX3226
In this chapter, you can understand how the configuration on Spanning Tree Protocol (STP) was
easily done. Compex SGX3226 implements Internet Group Multicast Protocol (IGMP) function
which forwards multicast traffic intelligently. In fact, Simple Network Management Protocol
(SNMP) is also introduced to provide a standard mechanism to monitor and control network
devices.
7.1 STP Config
Spanning Tree Protocol is a link management protocol that provides path redundancy
while preventing undesirable loops in the network. For an Ethernet network to
function properly, only one active path can exist between two stations.
Multiple active paths between stations cause loops in the network. If a loop exists in
the network topology, the potential exists for duplication of messages. When loops
occur, some switches see stations appear on both sides of the switch. This condition
confuses the forwarding algorithm and allows duplicate frames to be forwarded.
7.1.1 STP Port
When Compex SGX3226 first powers up, all bridges will declare
themselves to be the root. The one with the lowest priority will be the root.
The bridges will stop advertising themselves and use the BPDUs of the root
bridge.
During normal operation for Compex SGX3226, the ports are either
forwarding or disabling.
In a forwarding state, the network can send and receive frames which takes
about 50 seconds for a port to go from disabling to forwarding.
In a blocking state, the port is not forwarding frames, but will receive the
BPDUs.
Active ports which can forward frames on the root bridge are known as
designated ports.