CISCO-IF-EXTENSION-MIB

MIB Reference — IPNetwork Monitor · Updated September 14, 2026

All MIBsCISCO-IF-EXTENSION-MIB

Organization: Cisco Systems, Inc.

Last Updated: 2011-06-27

Category: Cisco Devices, Network Interfaces

Description: Provides Cisco-specific extensions to the standard interfaces MIB including link debounce and carrier-delay settings.

IPNetwork Monitor uses several OIDs from this MIB in network discovery and polling the applicable devices. Start monitoring CISCO-IF-EXTENSION-MIB with a free 30-day trial of IPNetwork Monitor.

What Is CISCO-IF-EXTENSION-MIB?

CISCO-IF-EXTENSION-MIB extends the IETF IF-MIB (RFC 2863) with Cisco-specific interface objects not available in standard interface MIBs, and formally replaces the legacy OLD-CISCO-INTERFACES-MIB. It exposes detailed per-interface packet-error statistics, including runts, giants, framing errors, overruns, ignored packets, abort errors, and input-queue drops, along with timestamps for last-in/last-out traffic and last-out-hang events, plus concepts like virtual switches, interface sharing, and speed groups relevant to Cisco's flexible interface architectures. This MIB is heavily used for monitoring interface hardware/software health: the various error counters reveal physical-layer problems such as bad cabling causing runts/giants or framing errors from clocking issues, and software-side congestion via input-queue drops, while the last-in/out timestamps and last-out-hang time help pinpoint exactly when an interface stopped forwarding traffic, useful for diagnosing an interface hang or reset event. It is explicitly built as an extension of and dependent on the IETF IF-MIB, adding detail the standard MIB omits rather than replacing its core interface table. It is deployed broadly on Cisco routers and switches, including those using virtual-switch/interface-sharing features, wherever deeper interface error diagnostics beyond ifTable/ifXTable are required. Engineers troubleshooting interface errors beyond the standard IF-MIB counters frequently look up the cisco-if-extension-mib specification for these additional diagnostic objects.

IPNetwork Monitor allows you to monitor SNMP objects defined in CISCO-IF-EXTENSION-MIB. Use the built-in SNMP Monitoring Browser to explore available variables, view their current values and descriptions, and select the objects you want to monitor. You can then create SNMP monitors, configure thresholds, and receive alerts when monitored values change.

Supported Devices

  • Cisco routers and switches

Monitoring Examples

A network engineer troubleshooting a flapping link would poll cieIfPacketStatsTable/cieIfPacketStatsEntry to compare cieIfInRuntsErrs and cieIfInGiantsErrs, which together with cieIfInFramingErrs would point to a cabling or duplex-mismatch problem versus a clocking issue. A sudden rise in cieIfInputQueueDrops without corresponding physical-layer errors would instead indicate the interface's inbound software queue is overwhelmed, often due to a CPU or QoS policy bottleneck rather than a wiring fault. Checking cieIfLastOutHangTime against cieIfLastOutTime would help confirm whether an interface actually froze at a specific time, correlating with a reported outage window.

What Can Be Monitored

  • input runt/giant packet errors
  • framing errors
  • input overruns and ignored packets
  • abort errors
  • input queue drops
  • last-in/last-out interface activity timestamps
Imported Objects

From CISCO-SMI

ciscoMgmtOBJECT-IDENTITY

From CISCO-TC

IfOperStatusReason

From ENTITY-MIB

entPhysicalIndexOBJECT-TYPE

From IF-MIB

InterfaceIndexOrZero
ifAdminStatusOBJECT-TYPE
ifIndexOBJECT-TYPE
ifNameOBJECT-TYPE
ifOperStatusOBJECT-TYPE
ifTypeOBJECT-TYPE

From SNMP-FRAMEWORK-MIB

SnmpAdminString

From SNMPv2-CONF

MODULE-COMPLIANCE
NOTIFICATION-GROUP
OBJECT-GROUP

From SNMPv2-SMI

Counter32
Counter64
Gauge32
Integer32
MODULE-IDENTITY
NOTIFICATION-TYPE
OBJECT-TYPE
Unsigned32

From SNMPv2-TC

DisplayString
TEXTUAL-CONVENTION
TimeStamp
TruthValue

How to Use in IPNetwork Monitor

Example using cieIfInRuntsErrs OID:

Select a Cisco router or switch as the target host to create a monitor — the SNMP service should be up and running on it. Click New Monitor, then check SNMP Custom on the Favorites tab, click Next, and confirm the host. On the next page, click Select... to open the built-in SNMP MIB Browser and type cieIfInRuntsErrs into the Find box to locate it in the OID tree, selecting the specific row/instance you want to monitor since this is a table column, then select it and click OK. The number of packets input on a particular physical interface which were dropped as they were smaller than the minimum allowable physical media limit. On the monitor's Main parameters page you can set the target's SNMP port (default 161), credentials, polling interval, and other settings — see the SNMP Monitor help for details. On the State conditions and Alerting tabs, configure when the monitor should change state and trigger an alert; since this is a Counter32-type OID, Value bounds is the most useful condition here — trigger an alert if the counter increases between polls, since a rising count of errors, failures, or discards often points to a real underlying problem. Click Finish to create the monitor; you can adjust any parameter later.
OIDs

RFC description

Cisco vendor extension MIB providing enhanced interface management objects beyond standard IF-MIB capabilities.

Start monitoring Cisco routers and switches with a free 30-day trial of IPNetwork Monitor. Import MIBs, browse SNMP OIDs, create custom SNMP monitors, configure alerts, and monitor any SNMP-enabled network device from a single console.

Download CISCO-IF-EXTENSION-MIB