Description

This article describes the issue of the 100GE interface displaying abnormal input PPS value with small packet sizes (approximately under 300 byte).

Symptoms

At times, the new 100GE interface is unable to display accurate input PPS value; whereas the output PPS displays the correct value. This issue is noticed with Junos 12.2R1.

user@mx480> show chassis hardware
FPC 4 REV 05 750-045372 -------- MPC Type 3
CPU REV 08 711-035209 -------- HMPC PMB 2G
MIC 1 REV 19 750-033199 -------- 1X100GE CFP
PIC 2 BUILTIN BUILTIN 1X100GE CFP
Xcvr 0 REV 01 740-032210 ------- CFP-100G-LR4
Packet size under 255 bytes :
user@mx480> show interfaces et-4/2/0
Input rate : 85714702288 bps ( 4043036 pps )
Output rate : 85714704272 bps (46992710 pps)

user@T4000> show chassis hardware
FPC 3 REV 01 750-045173 -------- FPC Type 5-3D
CPU REV 13 711-030686 ------- SNG PMB
PIC 0 REV 02 750-035293 -------- 1x100GE
Xcvr 0 REV 01 740-032210 -------- CFP-100G-LR4
Packet size under 128 bytes :
user@T4000> show interfaces et-3/0/0 extensive | match pps | match input
Input packets: 106381410354 124232 pps

Solution

This is a display error; so there is no impact on user traffic.

The fix for this issue is available in Junos 12.2R2 or later.