Version

Argent Advanced Technology 3.1A-1407-T2 and later

Date

Thursday, 14 Aug 2014

Summary

Device Magic is a new Argent product introduced in Argent AT 3.1A-1407-A

It automatically finds all the switch ports and query the port status

The results are display in Devices and Ports in real time

Sometimes ports are not found for some Cisco switches

This is caused by SNMP bugs in the Cisco OS

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Argent AT has implemented a workaround in 3.1A-1407-T2 and later

But there are performance costs for the workaround

By default, these workaround is turned off

To turn on, set the flag in Licensed Node Properties

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Technical Background

By default, Argent for SNMP traverses SNMP OID branch DOT1DBASEBRIDGEPORT (1.3.6.1.2.1.17.1.4.1) to find out all the switch ports

Unfortunately, the older Cisco OS has bugs that prevent all the ports from being listed

Apparently the issue won’t go away unless the switch firmware’s firmware is upgraded

The Argent workaround reads SNMP OID branch IFINDEX (1.3.6.1.2.1.2.2.1) first, then do a lot of other queries to map switch ports

Resolution

Upgrade to Argent Advanced Technology 3.1A-1407-T2 or later, and then turn on the flag ‘Do Not Use Bridge Port OIDs‘ for the device