No relevant resource is found in the selected language.

This site uses cookies. By continuing to browse the site you are agreeing to our use of cookies. Read our privacy policy>

Reminder

To have a better experience, please upgrade your IE browser.

upgrade

Packet Loss Occurs When an NE40E Pings an NE80 During Peak Hours

Publication Date:  2013-01-07 Views:  27 Downloads:  0
Issue Description

Based on the customer feedback, packet loss occurs only during peak hours                 


 

Handling Process

Based on the customer feedback, packet loss occurs only during peak hours. Therefore, the problem is not caused by a link failure.

Collect traffic statistics on the NE80 and run the ping command with the source address on the NE40E.

An example configuration on how to collect traffic statistics on the NE80 is shown as follows.

[NE80]acl 40001           

    [NE80-acl-simple-40001] rule icmp source 192.168.128.1 0.0.0.3 destination 192.168.128.2  0.0.0.3

    [NE80]traffic classifier  c100    //c100 specifies the name of the traffic classifier.

    [NE80-classifier-c100]if-match acl 40001   //Matches ACL 40001.

    [NE80]traffic  behavior b100    //b100 specifies the name of the traffic behavior.

    [NE80-behavior-b100]permit      

    [NE80]traffic policy p100   //p100 specifies the name of the traffic policy.

    [NE80-trafficpolicy-p100]classifier c100 behavior b100  //Associates the traffic classifier c100 with the traffic behavior b100.

   [NE80-Ethernet8/0/2]traffic-policy p100 {inbound | outbound}  //Applies the traffic policy p100 to the Layer 3 interface.

[NE80]commit traffic  policy//Validates the configuration of the traffic policy p100.

    [NE80]Display qos policy p100 {inbound | outbound} //To collect traffic statistics on the outbound interface, swap the source address with the destination address in the ACL.

Based on the traffic statistics collected on the NE80, there are fewer outgoing packets than incoming packets. It is preliminarily concluded that the problem is lies in the NE80 fault.

Since packet loss occurs only during peak hours, it is doubted that the forwarding capability on the LPU on the NE80 is insufficient. Run the following commands to view information at the bottom on the NE80.

    [NE80-diag]display efu 8 chipstatus  1 //Displays the number of idle threads on the NP. The value is an instant integer. Based on several checks of the value, if Total Idle=0 is displayed, the packet forwarding rate (in pps) has exceeded the NP forwarding capability. As a result, packet loss occurs.

   [NE80-diag]display efu 8 chipstatus  2 //Displays whether the upstream memory has exceeded the threshold.

   [NE80-diag]display efu 8 chipstatus  5 //Displays whether the upstream memory of the NP on the LPU has exceeded the threshold.

  [NE80-diag]display efu 8 chipstatus  2 //Displays whether backpressure occurs on the NP on the LPU. If backpressure occurs on the LPU, the traffic volume on the LPU is too large and therefore must be load balanced.

   TB Output Queue Grant P1 31:00 0xFFFF  //0xFFFF corresponds to the value of a backpressure signal on an LPU. 1 indicates that backpressure does not occur on the corresponding LPU. 0 indicates that backpressure occurs on the corresponding LPU.

total idle=0 is displayed in the command output, indicating that the total number of idle threads on the NP is insufficient. For details about the command output, see the following attachment.

If ping packet loss occurs during the peak hours, the traffic volume may be too large, exceeding the forwarding capability of the NE80.

Root Cause

If ping packet loss occurs during the peak hours, the traffic volume may be too large, exceeding the forwarding capability of the NE80.

 

Based on the analysis, the instant traffic volume is too large during the peak hours, far exceeding the forwarding capability of the LPU. Traffic shaping must be configured on the upstream device or the traffic must be load balanced between different LPUs on the NE80.

 

Solution

Expand the forwarding capability of the NE80 or configure traffic shaping on the upstream device.

END