DLSW-MIB

MIB Reference — IPNetwork Monitor · Updated September 09, 2026

All MIBsDLSW-MIB

Organization: AIW DLSw MIB RIGLET and IETF DLSw MIB Working Group

Last Updated: 1996-06-04

Category: VLAN and Bridging

Description: Defines managed objects for Data Link Switching (DLSw), a protocol that forwards SNA and NetBIOS traffic over TCP/IP networks.

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

What Is DLSW-MIB?

DLSW-MIB defines managed objects for Data Link Switching (dlsw), a protocol used to forward legacy SNA and NetBIOS traffic over TCP/IP networks by tunneling between DLSw peer nodes. It exposes node identity information, TCP connection statistics between DLSw peers, and per-node capability/status data. Its monitoring emphasis is on software/protocol-level health rather than physical hardware: dlswNodeStatus and dlswNodeUpTime reveal whether the DLSw process is operational and how long it has been running, while connection statistics like active, closed-idle, and closed-busy counts reveal peer connection churn and capacity issues. It is a standalone protocol MIB but is commonly deployed alongside standard interface and TCP/IP MIBs on the routers that terminate DLSw tunnels. It is typically found in enterprise networks that still bridge legacy mainframe SNA/NetBIOS traffic over modern IP backbones, often on branch or data-center routers.

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

  • routers and gateways running Data Link Switching (DLSw)
  • legacy SNA/NetBIOS-to-IP bridging devices

Monitoring Examples

An operator would check dlswNodeStatus and dlswNodeUpTime to confirm the DLSw process is up and has not recently restarted unexpectedly. Polling dlswTConnStatActiveConnections alongside dlswTConnStatCloseIdles and dlswTConnStatCloseBusys reveals whether DLSw TCP connections to peer routers are being torn down due to idleness or congestion, a sign of an unstable or oversubscribed DLSw tunnel. dlswNodeVendorID and dlswNodeVersionString help confirm interoperability between DLSw peers of different vendors during troubleshooting.

What Can Be Monitored

  • DLSw node operational status
  • node uptime
  • active DLSw peer connections
  • connection close counts (idle/busy)
  • node version and vendor identification
Imported Objects

From IF-MIB

ifIndexOBJECT-TYPE

From SNA-SDLC-MIB

sdlcLSAddressOBJECT-TYPE

From SNMPv2-CONF

MODULE-COMPLIANCE
NOTIFICATION-GROUP
OBJECT-GROUP

From SNMPv2-SMI

Counter32
Gauge32
MODULE-IDENTITY
NOTIFICATION-TYPE
OBJECT-TYPE
TimeTicks
mib-2

From SNMPv2-TC

DisplayString
RowPointer
RowStatus
TEXTUAL-CONVENTION
TruthValue

How to Use in IPNetwork Monitor

Example using dlswCircuitFCRecvCurrentWndw OID:

Select a router or gateway running Data Link Switching (DLSw) 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 dlswCircuitFCRecvCurrentWndw 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. It reports the current receive-side flow-control window size for this DLSw circuit — the number of additional paced messages this DLSw is currently authorizing its partner to send. 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 an INTEGER-type OID, Value bounds is the most useful condition here — trigger an alert if the window size stays persistently near zero, since that indicates sustained flow-control backpressure on this circuit. Click Finish to create the monitor; you can adjust any parameter later.

See also: dlswCircuitFCSendCurrentWndw, dlswNodeUpTime

OIDs

RFC description

Data Link Switch (DLSw) MIB (RFC 2024); manages switching of LAN protocols over WAN links.

Start monitoring Router/gateway running Data Link Switching (vendor-neutral, legacy SNA/NetBIOS over IP) 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 DLSW-MIB