3Com 3C13636 Configuration Manual page 368

3Com Router 3000 Ethernet Family
Configuration Guide
Table 3-21 Set the Forward Delay timer
Set the Forward Delay timer
Restore the default setting of the
Forward Delay timer
The default setting of the Forward Delay timer is 15 seconds.
When configuring a Forward Delay timer, consider the following:
On a spanning tree, all bridges must use the Forward Delay timer of the root
bridge instead of their own.
Use the default Forward Delay timer setting if possible. A small forward delay
may create temporary path redundancy; while a large forward delay may
increase the time required for the topology of the spanning tree to converge. In
the latter case, network connectivity recovery may take a long time.
VIII. Setting the Max Age timer (optional)
A Max Age timer is used to limit the lifetime of BPDUs. Enabling STP on a port starts a
Max Age timer. If the interface receives no BPDU before the timer expires, its link is
considered faulty and STP starts to recalculate its topology.
Perform the following configuration in system view.
Table 3-22 Set the Max Age timer
Set the Max Age timer
Restore default setting of the Max Age
timer
The default setting of the Max Age timer is 20 seconds.
When configuring a Max Age timer, consider the following:
On a spanning tree, all bridges use the Max Age timer of the root instead of their
own.
Set the timer appropriately. A small timer may result in undesired spanning tree
calculation frequency and have the bridge mistake congestions for link failures. A
large timer, on the contrary, may decrease the self-tuning capability of the
network preventing the bridge from discovering link failures quickly.
You are recommended to use the default Max Age timer setting in normal cases.
Operation
Operation
3Com Corporation
3-19
Chapter 3 Bridge Configuration
Command
bridge stp timer
seconds
undo bridge stp timer forward-delay
Command
bridge stp max-age seconds
undo bridge stp max-age
forward-delay