Configuring Snmp Ifindex Persistence; Understanding Snmp Ifindex Persistence - Cisco WS-SUP32-GE-3B - Supervisor Engine 32 Software Configuration Manual

Configuring SNMP IfIndex Persistence

This chapter describes how to configure the SNMP ifIndex persistence feature on Catalyst 6500 series
switches.
For complete syntax and usage information for the commands used in this chapter, refer to the
Note
Catalyst Supervisor Engine 32 PISA Cisco IOS Command Reference, Release 12.2ZY, at this URL:
http://www.cisco.com/en/US/docs/switches/lan/catalyst6500/ios/12.2ZY/command/reference/cmdref.h
tml
This chapter consists of these sections:
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Understanding SNMP IfIndex Persistence

The SNMP ifIndex persistence feature provides an interface index (ifIndex) value that is retained and
used when the switch reboots. The ifIndex value is a unique identifying number associated with a
physical or logical interface.
There is no requirement in the relevant RFCs that the correspondence between particular ifIndex values
and their interfaces be maintained when the switch reboots, but many applications (for example, device
inventory, billing, and fault detection) require maintenance of this correspondence.
You can poll the switch at regular intervals to correlate the interfaces to the ifIndexes, but it is not
practical to poll constantly. The SNMP ifIndex persistence feature provides permanent ifIndex values,
which eliminates the need to poll interfaces.
The following definitions are based on RFC 2233, "The Interfaces Group MIB using SMIv2." The
following terms are values in the Interfaces MIB (IF-MIB):
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OL-11439-03
Understanding SNMP IfIndex Persistence, page 49-1
Configuring SNMP IfIndex Persistence, page 49-2
ifIndex —A unique number (greater than zero) that identifies each interface for SNMP
identification of that interface.
ifName—The text-based name of the interface, for example, "ethernet 3/1."
ifDescr—A description of the interface. Recommended information for this description includes the
name of the manufacturer, the product name, and the version of the interface hardware and software.
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