Ping packet loss can be observed on a directly connected interface or with Fiber loop

Ping packet loss is observed when rapid ping is issued

On PTX10003-EVO devices with Software versions prior to 23.2R2, can notice the ping packet loss with rapid ping.

This is due to the lower value for the DDOS ICMP policer. The default DDOS ICMP policer value prior to 23.2R2 is 500 PPS.

As rapid ping initiates the Echo requests as soon as possible, there is higher chance of reaching the ICMP DDOS limit of 500 PPS on a directly connected interface or interfaces with the fiber loop.

In the below example

user@router> ping 192.168.1.255 rapid count 5000 source 192.168.1.1 bypass-routing

PING 192.168.1.255 (192.168.1.255) from 192.168.1.1 : 56(84) bytes of data.

....................

--- 192.168.1.255 ping statistics ---

3995 packets transmitted, 3975 received, 0.500626% packet loss, time 10502ms

rtt min/avg/max/mdev = 0.154/0.214/0.648/0.031 ms, ipg/ewma 2.629/0.211 ms


The Avg RTT value for the ping is 0.214 ms, Which indicates that the ping request and response times are very short, which results in larger ping packets being generated.


Solution: From 23.2R2 onwards the default ICMP DDOS value is increased to 2500 PPS.

Prior to 23.2R2, please configure the below statement to increase the ICMP DDOS policer value.


set system ddos-protection protocols icmp aggregate bandwidth 2500