Ethernet Switch User Manual
Manual_cmd_line_config-ESML6-P3-Rev1106
Copyright © KBC Networks Ltd.
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Where <1-2> is the hello time in seconds. The default value is 2. Hello time is the
interval of sending the BPDU periodically. It is set by the ROOT bridge and it is the same
for the whole network.
Setting bridge max age:
SWITCH(config)#rstp rstp max-age <6-40>
Where <6-40>is the message max age in seconds. The default value is 20.
The max age determines the time for one setting message being transmitted in the
network. Each setting message will contain a Configuration Message Age. The setting
message is generated in the ROOT. In the BPDU sent by ROOT, the message max age
will always be 0. When the message passes through one switch, the age will be
incremented by 1. When the message age is bigger than maximum age, the message will
be discarded. Max age limits the times a switch joins the RSTP calculation. The devices
with a hop count bigger than the max age will not be calculated in the present spanning
tree.
Setting protocol version:
SWITCH(config)#rstp rstp forceversion <0-2>
Where <0-2> is the current protocol version, 0 for STP, 2 for RSTP, 1 is not valid.
Note:
The value of Forward Delay, Max Age, and Hello Time should correspond with
following rules :
2 * (Bridge_Forward_Delay – 1.0 seconds) >= Bridge_Max_Age
Bridge_Max_Age >= 2 * (Bridge_Hell 1.0 seconds)
RSTP port configuration:
Enabling an RSTP port
SWITCH(config)#rstp port <1-10> enable
Where <1-10> is the port ID
Disabling an RSTP port
SWITCH(config)#rstp port <1-10> disable
Where <1-10> is the port ID
Setting the port path cost
SWITCH(config)#rstp port <1-10> path-cost <1-20000000>
Where <1-10>is the Port ID and <1-20000000> is the Path cost to the root port.
The Path cost is the shortest path cost between current port and root port. It is
determined by the bandwidth. The bigger the bandwidth is, the smaller the path cost will
be. Modifying the path cost will change the forwarding path from current device to the
root port.
