User Manual
Table Of Contents
- Intended Readers
- Icons for Note, Caution, and Warning
- I. Product Overview
- I-1 . Product Brief Description
- I-2. Product Specification
- I-3. Hardware Description
- I-4. DIN-Rail Mounting
- /I-5. Console Connection
- The Console port is for local management by using a terminal emulator or a computer with terminal emulation software.
- DB9 connector connect to computer COM port
- Baud rate: 115200bps
- 8 data bits, 1 stop bit
- None Priority
- None flow control
- I-6. Connecting Cable
- II. Preparing for Management
- III. Web Management
- III-1. Web Management - Overview
- III-2. Web Management – Basic Settings
- III-3. Web Management – Redundancy
- III-4. Web Management – Management
- III-5. Web Management – L2 Switching
- III-6. Web Management – Security
- III-7. Web Management – Diagnostics
- III-8. Web Management – Monitoring
- III-9. Web Management – MAC Table
- III-10. Web Management – Maintenance
- Appendix A: IP Configuration for Your PC
- Appendix B: CLI Command Reference
- Revision History
- Federal Communication Commission Interference Statement
- R&TTE Compliance Statement
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III-3. Web Management – Redundancy
III-3-1. REDUNDANCY – SPANNING TREE
The Spanning-Tree Protocol is a standard protocol that is defined in IEEE 802.1D. It is used to build
a logical loop-free topology for layer-2 Networks. The basic function of the protocol is to prevent loops
and broadcast flooding around the switches. STP allows spare links in the network design to
provide backup paths when the active link fails and requires a convergence time of 30-50 seconds to
recover the topology when the topology is changed. This prompted the use of Rapid Spanning-Tree
Protocol as it provides a faster convergence when the topology is changed.
RSTP was introduced by IEEE as 802.1w. It can respond within 3 x "Hello Time" when a topology is
changed. The "Hello Time" is a configurable value and it is very important for RSTP. The default RSTP
value is 2 seconds and typically, the convergence time for RSTP is under 6 seconds. RSTP is much faster
than STP. RSTP should be used instead of STP.
The Multiple Spanning-Tree Protocol defined in the IEEE 802.1s is an extension to RSTP for Virtual LANs.
MSTP provides a better alternate path than STP/RSTP for different VLANs. It can make a group of VLANs
more systemized in the topology.
C
ONFIGURE RSTP BASIC IN FO RMATION
•
System Time Information
RSTP: Enable STP and run "RSTP" for redundancy.
MSTP: Enable STP and run "MSTP" for redundancy.
Disable: Disable STP. Users have to enable another protocol to prevent from loop.
•
Root Priority
It is used to define the "Root Bridge". The bridge with the lowest Root Priority is the "Root Bridge".
If all the bridges are set to the same Root Priority value, the system will select the Root Bridge based
on the MAC Addresses.
The range of Root Priority is from 0 to 61440(multiple of 4096).
The default Root Priority is 32768.
•
Hello Time
It is very important and used to determine the interval to send BPDU (management frame) to check
the RSTP topology and status.
The range of Hello Time is from 1 to 10 second(s).
The default Hello Time is 2 seconds.
•
Forward Delay
A delay/timer is used to determine when to change the Path State from Learning/Listening to
Forwarding.
The range of Forward Delay is from 4 to 30 seconds.
The default Forward Delay is 15 seconds.