User Manual

S350 Series 24-Port (PoE+) and 48-Port Gigabit Ethernet Smart Switches
Configure Switching User Manual147
The System Information page displays.
5. Select Switching > STP >
Advanced > CST Configuration.
6. Specify the CST options:
• Bridge Priority. When switches or bridges are running STP
, each is assigned a
priority. After exchanging BPDUs, the switch with the lowest priority value becomes
the root bridge. Specify the bridge priority value for the Common and Internal
Spanning Tree (CST). The range is from 0 to 61440. The bridge priority is a multiple
of 4096. If you specify a priority that is not a multiple of 4096, the priority is
automatically set to the next lowest priority that is a multiple of 4096. For example, if
you set the priority to any value between 0 and 4095, the switch automatically sets
the value to 0. The default value is 32768.
• Bridge Max Age (secs).
The bridge maximum age time for the Common and Internal
Spanning Tree (CST), which indicates the time in seconds a bridge must wait before
implementing a topological change. The range is from 6 to 40, and the value must be
less than or equal to (2 * Bridge Forward Delay) – 1 and greater than or equal to 2 *
(Bridge Hello Time +1). The default value is 20.
• Bridge Hello Time (secs).
The bridge hello time for the Common and Internal
Spanning Tree (CST), which indicates the time in seconds a root bridge must wait
between configuration messages. The value is fixed at 2 seconds. The value must be
less than or equal to (Bridge Max Age / 2) – 1. The default hello time value is 2.
• Bridge Forward Delay (secs).
The bridge forward delay time, which indicates the
time in seconds a bridge must remains in a listening and learning state before
forwarding packets. The value must be greater or equal to (Bridge Max Age / 2) + 1.
The time range is from 4 seconds to 30 seconds. The default value is 15 seconds.
• Spanning Tree Maximum Hops.
The maximum number of bridge hops the
information for a particular CST instance can travel before being discarded. The
range is from 6 to 40. The default is 20 hops.
7. Click the Apply button.
Your settings are saved.
8. T
o refresh the page with the latest information about the switch, click the Refresh button.