SNA-LLC-MIB

MIB Reference — IPNetwork Monitor · Updated September 09, 2026

All MIBsSNA-LLC-MIB

Category: Legacy and Compatibility MIBs, SNA and Legacy WAN Protocols

Description: Manages SNA LLC (Logical Link Control) layer configuration, connection endpoints, and frame statistics.

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What Is SNA-LLC-MIB?

SNA-LLC-MIB is an IETF standards-based MIB managing IEEE 802.2 Logical Link Control (LLC) layer configuration and status, historically associated with IBM SNA-over-LAN environments. It exposes an administrative port table (llcPortAdminTable) for configuring per-port LLC parameters such as maximum I-PDU sizes, unacknowledged I-PDU limits, retransmission counts, and various protocol timers (ack, P-bit, reject), plus a corresponding operational table reflecting the values actually in effect. Its monitoring value lies in verifying LLC connection/session-layer software configuration and behavior: administrators compare admin versus operational settings to detect a port waiting on a pending configuration change (since some parameters only take effect after interface restart), and can track frame/connection statistics to spot LLC-layer errors like excessive retransmissions or timer expirations signaling link-layer instability. It is a standards-track companion to the base SNA (Systems Network Architecture) DLC MIB framework and depends on that broader SNA MIB family's object model. It is deployed on legacy SNA gateway devices, front-end processors, or routers providing SNA-over-LAN LLC connectivity in IBM mainframe-integrated enterprise networks. Network engineers evaluating or troubleshooting this functionality can download the SNA-LLC-MIB file directly to load it into their MIB browser.

IPNetwork Monitor allows you to monitor SNMP objects defined in SNA-LLC-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
  • SNA gateway or front-end processor supporting LLC over LAN

Monitoring Examples

An administrator would compare llcPortAdminTable entries (llcPortAdminMaxIPDUOctetsSend, llcPortAdminMaxUnackedIPDUsSend, llcPortAdminMaxRetransmits) against the corresponding llcPortOperTable values to detect a port still running with stale operational parameters because the admin change is pending an interface restart. A rising llcPortAdminMaxRetransmits ceiling being repeatedly hit, together with llcPortAdminAckTimer or llcPortAdminRejTimer expirations, would reveal LLC-layer session instability such as a flaky link or an overloaded remote SNA endpoint. llcPortAdminState indicates whether a given LLC port is enabled at all.

What Can Be Monitored

  • LLC port admin state
  • max I-PDU send/receive size
  • max unacknowledged I-PDUs
  • max retransmit count
  • ack/P-bit/reject timer settings
Imported Objects

From RFC-1212

OBJECT-TYPE

From RFC-1215

TRAP-TYPE

From RFC1213-MIB

ifIndex

From SNMPv2-SMI

Counter32
Integer32
TimeTicks
experimental

From SNMPv2-TC-v1

DisplayString
RowStatus
OIDs

RFC description

LLC (Logical Link Control) device management for SNA/DLC networks. Manages port administration, SAP parameters, and data link control.

Start monitoring vendor-neutral, standards-based MIB, SNA gateway or front-end processor supporting LLC over LAN (802.2 LLC port 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 SNA-LLC-MIB