Network Diameter Configuration; Mstp Time-Related Configuration - H3C S7500 Series Operation Manual

Operation Manual – MSTP
H3C S7500 Series Ethernet Switches

1.2.7 Network Diameter Configuration

In a switched network, any two switches can communicate with each other through a
path, on which there may be some other switches. The network diameter of a network
is measured by the number of switches; it equals the number of the switches on the
longest path (that is, the path containing the maximum number of switches).
I. Configuration procedure
Follow these steps to configure the network diameter for a network:
Enter system view
Configure the network
diameter for a network
The network diameter parameter indicates the size of a network. The larger the network
diameter is, the larger the network size is.
After you configure the network diameter of a switched network, an MSTP-enabled
switch adjusts its Hello time, Forward delay, and Max age settings accordingly.
The network diameter setting only applies to the CIST and it is invalid for MSTIs.
II. Configuration example
# Configure the network diameter of the switched network to 6.
<H3C> system-view
[H3C] stp bridge-diameter 6

1.2.8 MSTP Time-related Configuration

You can configure three MSTP time-related parameters for a switch: Forward delay,
Hello time, and Max age.
The Forward delay parameter sets the delay of state transition.
Link failures in a network result in the spanning trees being regenerated and original
spanning tree structures being changed. As the newly generated configuration BPDUs
cannot be propagated across the entire network immediately when the new spanning
trees are generated, loops may occur if the new root ports and designated ports begin
to forward packets immediately.
This problem can be avoided by adopting a state transition mechanism. With this
mechanism, newly selected root ports and designated ports undergo an intermediate
state before they begin to forward packets. That is, it costs these ports a period
(specified by the Forward delay parameter) for them to turn to the forwarding state. The
To do ...
system-view
stp bridge-diameter
bridgenumber
Use the command ...
1-15
Chapter 1 MSTP Configuration
Remarks
—
Required
The default network
diameter of a network is 7.