Spectrum displays SysUptime in OneClick and SRM incorrectly for devices that have been up for more then 497 days

Products

• Spectrum

Issue/Introduction

We noticed that the Last Reboot Time was incorrect in our SRM assets report and we can also see that the System Up Time in OneClick is not correct for devices that have been up for more then 497 days.  Why are we seeing this discrepancy?

Environment

Release : 10.x, 20.x, 21.x

Component : Spectrum Reporting / Spectrum OneClick

Cause

System Up Time in OneClick as well as Last Reboot Time in SRM are both based upon sysUpTime value.

 

RFC1213 defines sysUpTime as a 32-bit counter in 1/100 second.  From the RFC's definition of sysUpTime:  "The time (in hundredths of a second) since the network management portion of the system was last re-initialized."

 

SysUpTime MIB supports 32-bit = 2 to the 32nd power = 2^32 = 4294967296 (Timeticks)
Converting time ticks to days = ((((4294967296 /60 seconds )/60 minutes )/24 hours )/100 ticks per second) = 497.1 days.

Resolution

This is currently FAD (Functioning as Designed) due to the limitations of using sysUpTime as being a 32bit attribute and we would recommend to not allow your devices reach more then 497 days with sysUpTime in order to avoid discrepancies.

Additional Information

We have tried to change the dependency of sysUpTime with SNMP Engine Time, however we are not able to implement this in Spectrum and SRM due to the following reasons.

 

1. Not all devices use SNMP Engine Time and this attrfibute would be blank for those devices.

2. The SNMP Engine Time relates to daemon process start time and not.to device start/stop time.