TN3270E-MIB

MIB Reference — IPNetwork Monitor · Updated September 09, 2026

All MIBsTN3270E-MIB

Organization: TN3270E Working Group

Last Updated: 1998-07-27

Category: SNA and Legacy Protocols

Description: Defines managed objects for configuring and managing TN3270E servers, covering server control, resource configuration, and client address mappings.

IPNetwork Monitor uses several OIDs from this MIB in network discovery and polling the applicable devices. Start monitoring TN3270E-MIB with a free 30-day trial of IPNetwork Monitor.

What Is TN3270E-MIB?

TN3270E-MIB is an IETF standards-based MIB (RFC 2562) defining managed objects for TN3270E servers, which act as terminal-emulation gateways allowing TCP/IP clients to reach IBM mainframe 3270 sessions over Telnet. It exposes configuration data for each TN3270E server instance - inactivity and activity timeouts, supported protocol functions, and administrative controls - alongside operational status objects reporting server admin/operational state and session termination state. Its monitoring value lies squarely in software/service status: whether the TN3270E server process is administratively up and operationally running, how sessions are terminating, and whether activity-check timeouts are properly enforced - there is no hardware sensor data in this module. As a vendor-neutral IETF MIB it is commonly deployed alongside standard host/network MIBs (e.g. IF-MIB, HOST-RESOURCES-MIB) on the underlying gateway system. It is typically deployed on TN3270E gateway/protocol-converter servers bridging modern IP networks to legacy IBM SNA/3270 mainframe access. Engineers can download the TN3270E-MIB file directly to load it into their MIB browser.

IPNetwork Monitor allows you to monitor SNMP objects defined in TN3270E-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 IETF MIB (RFC 2562), not tied to a specific manufacturer
  • TN3270E gateway/protocol converter servers bridging IP networks to IBM mainframe 3270 sessions

Monitoring Examples

A network operator would poll tn3270eSrvrConfTable (tn3270eSrvrConfEntry) to compare tn3270eSrvrConfOperStatus against tn3270eSrvrConfAdminStatus for a given tn3270eSrvrConfIndex, confirming the TN3270E server is actually running when administratively enabled. Watching tn3270eSrvrConfSessionTermState reveals whether client sessions end normally or are abnormally torn down, while tn3270eSrvrConfActivityTimeout and tn3270eSrvrConfInactivityTimeout confirm idle-session cleanup is configured as expected; tn3270eSrvrFunctionsSupported indicates which TN3270E protocol extensions a server instance offers.

What Can Be Monitored

  • server admin/operational status
  • session termination state
  • activity and inactivity timeout settings
  • supported TN3270E protocol functions
  • number of configured server instances
Imported Objects

From IANATn3270eTC-MIB

IANATn3270DeviceType
IANATn3270Functions
IANATn3270ResourceType
IANATn3270eAddrType
IANATn3270eAddress
IANATn3270eClientType
IANATn3270eLogData

From SNA-NAU-MIB

snanauMIBMODULE-IDENTITY

From SNMP-FRAMEWORK-MIB

SnmpAdminString

From SNMPv2-CONF

MODULE-COMPLIANCE
OBJECT-GROUP

From SNMPv2-SMI

Counter32
Counter64
Gauge32
IpAddress
MODULE-IDENTITY
OBJECT-TYPE
TimeTicks
Unsigned32

From SNMPv2-TC

DateAndTime
RowStatus
TEXTUAL-CONVENTION
TestAndIncr
TimeStamp

From SYSAPPL-MIB

Utf8String

How to Use in IPNetwork Monitor

Example using tn3270eSrvrStatsInConnects OID:

Select a device implementing TN3270E-MIB 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 tn3270eSrvrStatsInConnects 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. Indicates the number of client (TCP) connections that succeeded at a TN3270E server for the granularity of this conceptual row (server-wide, port, or port-and-local-address). 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

Manages TN3270E servers supporting terminal emulation over TCP/IP networks with session and resource tracking.

Start monitoring vendor-neutral, standards-based IETF MIB (RFC 2562), TN3270E gateway/protocol converter servers (server admin/session status) 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 TN3270E-MIB