Stp Timer Forward-Delay - Huawei Quidway S8500 Series Command Manual

Command Manual – STP
Quidway S8500 Series Routing Switches
When the protection from TC-BPDU packet attack is enabled, the switch just perform
one delete operation in a specified period (generally, 15 seconds) after receiving
TC-BPDU packets, as well as monitoring whether it receives TC-BPDU packets during
this period. Even if it detects a TC-BPDU packet is received in a period shorter than the
specified interval, the switch shall not run the delete operation till the specified interval
is reached. This can avoid frequent delete operations to the MAC address table and
ARP table.
Example
# Enable TC-BPDU protection on the switch.
<Quidway>system-view
System View: return to User View with Ctrl+Z.
[Quidway] stp tc-protection enable

1.1.38 stp timer forward-delay

Syntax
stp timer forward-delay centi-senconds
undo stp timer forward-delay
View
System view
Parameter
centi-senconds: Specifies Forward Delay, which is in the range from 400 to 3000 and
measured in centiseconds. By default, the Forward Delay of the switch is 1500
centiseconds.
Description
Use the stp timer forward-delay command to configure Forward Delay for the switch.
Use the undo stp timer forward-delay command to restore the default Forward Delay.
To avoid temporary loop, MSTP defines a medium state, Learning, when the port
switches from the Discarding state to Forwarding state. There is also a delay before
state switchover to guarantee the synchronous switchover with the remote switch. The
Forward Delay configured on the root bridge determines the state transition time.
The root bridge will determine the state transition time according to the configured
values, while the other switches will apply the forward delay configured on it.
When configuring Hello time, Forward Delay and Max Age, guarantee the following
equations:
2 x (Forward Delay - 1.0 second) >= Max Age
Huawei Technologies Proprietary
1-39
Chapter 1 MSTP Configuration Commands