Industrial Ethernet Switch User Manual
3onedata proprietary and confidential
33
Copyright © 3onedata Co., Ltd.
Rapid Spanning Tree of concepts:
Switch priority
：
As the bridge priority
，
the bridge priority and bridge MAC
address combine bridge ID
，
the smallest ID bridge will become the root bridge
on the network.
Polling interval
：
how often send BPDU packet at one time.
Forwarding delay
：
the port state of switch remain a forward delay time over the
listening and learning.
The maximum aging time
：
After one switch receive a packet from other
switches , how long the packet is valid
The port concepts of RSTP:
Port path overhead
：
port link cost compared with port priority and port ID .
Port priority
：
port priority among the net bridge compared with port priority and
port ID.
Point to point network connection
：
directly connect with switches port each
other ,the port is P2P,which adopted negotiation mechanism,RSTP can achieve
port state rapid conversion RSTP.
Directly connect terminal
：
connect the edge of network switch with terminal
devices with
configuration Edge port
，
which can achieve port state rapid
conversion without the processing Discarding
，
Learning
，
Forwarding.
Don’t join RST structure
：
don’t participate in RSTP running.
RSTP switch port states:
Blocking
- A port that would cause a switching loop if it were active. No user data
is sent or received over a blocking port, but it may go into forwarding mode if the
other links in use fail and the spanning tree algorithm determines the port may
transition to the forwarding state. BPDU data is still received in blocking state.
Prevents the use of looped paths.
Listening
- The switch processes BPDUs and awaits possible new information
that would cause it to return to the blocking state. It does not populate the MAC
address table and it does not forward frames.
Learning
- While the port does not yet forward frames it does learn source
addresses from frames received and adds them to the filtering database
(switching database). It populates the MAC Address table, but does not forward
frames.
Forwarding
- A port receiving and sending data, normal operation. RSTP still
monitors incoming BPDUs that would indicate it should return to the blocking
state to prevent a loop.
The example of Configuration: The priority of network bridge is “32768”
，
If there did
not have network ID less than itself, itself is root network bridge. There did not have
same network ID in network. Every 2 seconds, the network bridge will transmit BPDU
