Packets being dropped on uplinks of CE6851

Hello everyone,

Today, I will introduce how to handle the uplink packet loss problem of CE switches.

Alarm Information

The burst traffic extends buff with packets loss logs:

Handling Process

1. From the logs we found there have many packets drop: 

ToR-1：From Aug  7 2018 there have packets drop in 10GE1/0/48.

Aug  7 2018 14:28:21+03:00 HQ-ToR-1 %QOS/6/QOS_PACKET_DROP(l):CID=0x807f042d;The forwarding engine detects packet discard.(Slot=1, Discard place=Panel Port Ifindex[52] Queue[0], Current discard=781)

ToR-2：From Aug 29 2018 there have packets drop in 10GE1/0/48.

Aug 29 2018 13:09:42+03:00 DR-ToR-2 %QOS/6/QOS_PACKET_DROP(l):CID=0x807f042d;The forwarding engine detects packet discard.(Slot=1, Discard place=Panel Port Ifindex[52] Queue[0], Current discard=1274)

burst traffic extend and packets drop:

2. From the configuration we found customer have 6*10ge port connect to server, But there only 1*10GE as a uplink, If there have any burst traffic.it will cause the drop in milliseconds.

3. The burst traffic extends buff with packets loss logs:

Root Cause

The burst traffic extend buffering cause the packets drop

Solution

1. Enable the traffic buffering to the enhanced mode in discard port example: (interface which face the packets drop issue)

<HUAWEI> system-view

[~HUAWEI] interface 10ge 1/0/1

[~HUAWEI-10GE1/0/1] qos burst-mode enhanced

http://support.huawei.com/hedex/pages/EDOC110002054831180AFU/02/EDOC110002054831180AFU/02/resources/dc/qos_burst-mode_interface_view.html?ft=0&fe=10&hib=12.1.17.4.14&id=qos_burst-mode_interface_view&text=qos%20burst-mode%20(interface%20view)&docid=EDOC1100020548 

2. Increase the link bandwidth, Example Change the uplink from 10GE to 40GE link

That is all I want to share with you!