stp timer forward-delay
Use stp timer forward-delay to set the forward delay timer.
Use undo stp timer forward-delay to restore the default.
Syntax
stp [ vlan vlan-id-list ] timer forward-delay time
undo stp [ vlan vlan-id-list ] timer forward-delay
Default
The forward delay timer is 1500 centiseconds.
Views
System view
Predefined user roles
network-admin
mdc-admin
Parameters
vlan vlan-id-list: Specifies a space-separated list of up to 10 VLAN items. Each item specifies a VLAN or a range of VLANs in the form of vlan-id1 [ to vlan-id2 ]. The value for vlan-id2 must be equal to or greater than the value for vlan-id1. The value range for the vlan-id argument is 1 to 4094. If you set the STP, RSTP, or MSTP forward delay, do not specify this option.
time: Specifies the forward delay in centiseconds, in the range of 400 to 3000 in increments of 100 (as in 400, 500, 600).
Usage guidelines
The forward delay timer determines the time interval of state transition. To prevent temporary loops, a spanning tree port goes through the learning (intermediate) state before it transits from the discarding state to the forwarding state. To stay synchronized with the remote device, the port has a wait period that is determined by the forward delay timer between transition states.
As a best practice, do not set the forward delay with this command. Instead, you can specify the network diameter of the switched network by using the stp bridge-diameter command. This command makes the spanning tree protocols automatically calculate the optimal settings for the forward delay timer. If the network diameter uses the default value, the forward delay timer also uses the default value.
Examples
# In MSTP mode, set the forward delay timer to 2000 centiseconds.
<Sysname> system-view [Sysname] stp timer forward-delay 2000
# In PVST mode, set the forward delay timer for VLAN 2 to 2000 centiseconds.
<Sysname> system-view [Sysname] stp vlan 2 timer forward-delay 2000
Related commands
stp bridge-diameter
stp timer hello
stp timer max-age