RS232-MIB

MIB Reference — IPNetwork Monitor · Updated September 09, 2026

All MIBsRS232-MIB

Category: Serial Interface

Description: Manages RS-232 serial interface configuration, control signals, and port statistics.

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What Is RS232-MIB?

RS232-MIB is a vendor-neutral IETF standards-based MIB (RFC 1659) for managing RS-232-C and related EIA/TIA serial interfaces on any device that exposes serial ports for out-of-band management. It defines objects for serial port configuration such as baud rate, parity, and flow control, along with modem/DTE-DCE control signal states and per-port input/output statistics. Its monitoring value lies in verifying that a serial console or async port's control signaling and configuration match expectations and in tracking traffic/error counters on that port -- a hardware-interface-status MIB for legacy serial connectivity rather than one covering CPU, memory, or environmental sensors. It is a standalone IETF standards MIB but is commonly used together with the CHARACTER-MIB and IF-MIB conventions on devices that expose serial ports through ifTable. It is typically deployed on routers, terminal servers, and other network equipment offering RS-232 console or auxiliary ports. Engineers implementing or auditing this functionality typically reference the RS232-MIB RFC/standard documentation for the authoritative specification.

IPNetwork Monitor allows you to monitor SNMP objects defined in RS232-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

  • vendor-neutral, standards-based MIB, not tied to a specific manufacturer
  • any network device with RS-232 serial/console ports (routers, terminal servers, modems)

Monitoring Examples

No object or table names were captured for this MIB (sample_objects is empty), so a specific polling example cannot be given with confidence. RFC 1659 defines an rs232PortTable/rs232PortEntry-style structure for per-port configuration and control-signal status, which an administrator would poll to confirm DTR/DCD signal state and detect a disconnected serial console session, but this is based on the well-known RFC structure rather than grounded sample data.

What Can Be Monitored

  • serial port configuration (baud rate, parity, flow control)
  • control signal states (DTR/DCD/RTS/CTS)
  • input/output byte and error counts
  • port connection status
Imported Objects

From RFC-1212

OBJECT-TYPE

From RFC1155-SMI

Counter
experimental
OIDs

RFC description

Standard SNMP MIB (RFC 1659) for managing RS-232 serial ports on network devices. Defines management objects for monitoring and configuring serial port parameters, line characteristics, and port status.

Start monitoring vendor-neutral, standards-based MIB, any network device with RS-232 serial/console ports 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 RS232-MIB