QTECH
Software Configuration Manual
15-198
! Configure the priority of the switch in spanning tree to 30000
QTECH(config)#spanning-tree priority 30000
Caution : If the priorities of all network bridge in switching network are the same,
choose the one with the smallest MAC address to be the root. If STP enables, configuring
network bridge may cause the re-accounting of the STP. By default, the network bridge
priority is 32768 and ranges from 0 to 65535.
15.2.5
Configure switch Forward Delay
When this switch is the root bridge, port state transition period is the Forward Delay time, which is
determined by the diameter of the switched network. The longer the diameter is, the longer the time is. Configure it in
global configuration mode :
Configure Forward Delay
spanning-tree forward-time
seconds
Restore default Forward Delay
no spanning-tree forward-time
For example :
! Configure forward delay to 20 seconds
QTECH(config)#spanning-tree forward-time 20
Caution : If Forward Delay is configured too small, temporary redundancy will becaused; if Forward
Delay is configured too large, network will not be restored linking for a long time. Forward Delay ranges from 4 to
30 seconds. The default forward delay time, 15 seconds is suggested to use. Forward Delay>=Hello Time + 2.
15.2.6
Configure Hello Time
Suitable Hello Time can guarantee network bridge noticing link failure in time without occupying too much
resources. Configure it in global configuration mode :
Configure Hello Time
spanning-tree hello-time
seconds
Restore default Hello Time
no spanning-tree hello-time
For example :
! Configure Hello Time to 5 seconds
QTECH(config)#spanning-tree hello-time 5
Caution : Too large Hello Time may cause link failure thought by network bridge for losing packets
of the link to restart accounting STP; too smaller Hello Time may cause network bridge frequently to send
configuration packet to strengthen the load of network and CPU. Hello Time ranges from 1 to 10 seconds. It is
suggested to use the default time of 2 seconds. Hello Time
≤
Forward Delay – 2
15.2.7
Configure Max Age
Max Age is used to judge whether the packet is outdate. User can configure it according to the real situation
of the network in global configuration mode :
Configure Max Age
spanning-tree max-age
seconds
Restore the default Max Age
no spanning-tree max-age
