User Manual

8-Port or 16-Port Gigabit Smart Managed Pro Switch Model GS418TPP, GS510TLP, and GS510TPP
Configure Switching User Manual167
Spanning Tree (CST). The valid range is 0–61440. 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 T
ree (CST), which indicates the time in seconds a bridge must wait before
implementing a topological change. The valid range is 6–40, 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 T
ree (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 valid
range is 6–40.
The default is 20 hops.
7. Click the Apply button.
Your settings are saved.
The following table describes the MSTP Status information that is displayed.
Table 38. STP advanced CST configuration, MSTP status
Field Description
MST ID Table consisting of the MST instances (including the CST) and the
corresponding VLAN IDs associated with each of them.
VID ID Table consisting of the VLAN IDs and the corresponding FID
associated with each of them.
FID ID Table consisting of the FIDs and the corresponding VLAN IDs
associated with each of them.
Configure the CST port settings
You can configure a common spanning tree (CST) and internal spanning tree on a specific
port on the switch.
A port can become diagnostically disabled (D-Disable) when DOT1S experiences a severe
error condition. The most common cause is when the DOT1S software experiences BPDU
flooding. The flooding criteria are such that DOT1S receives more than 15 BPDUs in a
3-second interval. The other causes for DOT1S D-Disable are extremely rare.