Operation Manual – User Access
H3C SecPath Series Security Products
Chapter 1 PPP Configuration
1-12
1.2.5 Configuring PPP Link Quality Control
You may use PPP link quality control (LQC) to monitor quality of PPP links. The system
shuts down a link when its quality decreased below the forbidden-percentage and
brings it up when its quality ameliorates exceeding the resumptive-percentage. When
re-enabling the link, PPP LQC experiences a delay to avoid link flapping.
Perform the following configuration in interface view.
Table 1-14
Configure PPP link quality control
Operation
Command
Enable PPP LQC
ppp lqc
forbidden-percentage
[
resumptive-percentage
]
Disable PPP LQC
undo ppp lqc
By default, the arguments
resumptive-percentage
and
forbidden-percentage
are equal.
Note:
Before you enable LQC, the PPP interface sends keepalive packets to the peer
regularly. After you enable LQC on the interface, the PPP interface sends link quality
reports (LQRs) instead for monitoring the link.
When the quality of the link is normal, the system calculates link quality based on each
LQR and shuts down the link if the results of two consecutive calculations are below the
forbidden-percentage. After shutting down the link, the system calculates link quality
every ten L QRs, and brings the link up again if the results of three consecutive
calculations are higher than the resumptive-percentage. That means a disabled link
must experience 30 keepalive periods before it can go up again. If a large keepalive
period is specified, it may take long time for the link to go up.
1.2.6 Displaying and Debugging PPP
When finishing the above configuration, execute
display
commands in all views to
view running status after the PPP configuration and to verify the effect of the
configuration. And you can debug PPP by executing
debugging
command in user
view.
Table 1-15
Displaying and debugging
Operation
Command
Display the PPP
configuration and status
of a interface
display
interface
interface-name
