ppp keepalive (Virtual template view)
Function
The ppp keepalive command configures a PPP detection interval and the maximum number of retransmission times allowed.
The undo ppp keepalive command restores the default PPP detection interval and the default maximum number of retransmission times allowed.
By default, the PPP detection interval is 20s, and the maximum number of retransmission times is 3.
This command is supported only on the NetEngine 8000 F1A.
Parameters
| Parameter | Description | Value |
|---|---|---|
| interval interval-time |
Specifies a PPP detection interval at which Echo-Request packets are sent to users. |
The value is an integer ranging from 0 to 65535, in seconds. The value 0 indicates that PPP detection is not implemented. when a specified value is smaller than the default value, it may cause high CPU usage and overburden the system. |
| retransmit times |
Specifies the maximum number of retransmission times allowed. |
The value is an integer ranging from 1 to 10. The default value is 3. when a specified value is smaller than the default value, it may cause high CPU usage and overburden the system. |
| response-timeout response-timeout-time |
Specifies the wait time for Echo-Ack packets from users. |
The value is an integer ranging from 1 to 65535, in seconds. |
| datacheck |
Indicates optimized PPP detection. By default, optimized PPP detection is disabled. |
- |
| no-datacheck |
Indicates that optimized PPP detection is disabled. Specifically, if a PPP server receives user traffic, it sends Echo-Request packets to the user for a specified number of times. If no response is received, the PPP server considers the user offline. If optimized PPP detection is disabled and responses to Echo-Request packets are not received in time, the PPP server may incorrectly consider the user offline. |
- |
Usage Guidelines
Usage Scenario
To configure a PPP detection interval and the maximum number of retransmission times allowed, run the ppp keepalive command. This function detects the PPP link status and online status of users. The device sends Echo-Request packets to a user at intervals. If·no response to the Echo-Request packets is received within a specified period, the device retransmits Echo-Request packets. If there is still no response from the user after the Echo-Request packets are retransmitted for a specified number of times, the device considers the user status abnormal. When both interval <interval-time> (the value is not zero) and response-timeout <response-timeout-time> are configured, interval <interval-time> takes effect at the first time, the smaller value between the two parameter values takes effect from the second time.
Configuration Impact
Set a longer PPP detection interval and a greater number of retransmission times in the case the network is unstable or low delay is needed. However, a longer PPP detection interval may cause the device to fail to detect the PPP link failure in time. During this period, the users may fail to access the Internet.
If the PPP detection packet transmission interval is short or a small number of retransmission times is set, PPP users may frequently go offline when network congestion occurs. Therefore, setting a long PPP detection interval is recommended in the case of network congestion. If the ppp keepalive command is run more than once in the same view, the latest configuration overrides the previous one.Precautions
In VS mode, this command is supported only by the admin VS.
The optimized PPP detection function takes effect only in slave core detection scenarios. when a specified value is smaller than the default value, it may cause high CPU usage and overburden the system, users may be logged out upon a detection timeout.Example
<HUAWEI> system-view [~HUAWEI] interface virtual-template 10 [*HUAWEI-Virtual-Template10] ppp keepalive interval 40 retransmit 4
<HUAWEI> system-view [~HUAWEI] interface virtual-template 10 [*HUAWEI-Virtual-Template10] ppp keepalive interval 10 retransmit 2 Warning: The keepalive interval value is less than 20 or retransmit value is less than 3. This operation may cause high CPU usage and overburden the system .Continue? [Y/N]: