Version

Argent Advanced Technology 3.1A-1601-C and earlier

Date

Monday, 15 February 2016

Summary

When running DeviceMagic Rule, Engine might occasionally report switch port is down or port status changed to unknown status ‘0’

According to RFC1213, switch port can only have valid statuses – 1 (running), 2 (down) and 3 (testing)

Value ‘0’ is undocumented due to communication error and should not be counted as error status

The issue has been addressed in Argent AT 3.1A-1601-T2

Technical Background

SNMP is a UDP based protocol

The UDP packets might be dropped by router, bridge or gateway when traffic is heavy

The undocumented status value ‘0’ is caused by such network traffic condition

Argent AT 3.1A-1601-T2 implements a retrial mechanism to minimize the chance that unknown status is retrieved

Also, Engine ignores such unknown status if network is constantly congested and waits for next checking time to test again

Resolution

Upgrade to Argent AT 3.1A-1601-T2 or later