All MIBs › NBS-VLAN-FWD-MIB
Organization: NBS
Last Updated: 2010-11-12
Category: LAN Management, VLAN Management
Description: Configures VLAN forwarding tables and port membership for Layer 2 switching on NBS equipment.
Start monitoring vendor-neutral, standards-based MIB, any SNMPv3-capable network device (SNMP engine identity/boot/clock 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.
What Is NBS-VLAN-FWD-MIB?
NBS-VLAN-FWD-MIB is a Layer 2 Ethernet switching MIB used by managed switches (the NBS naming traces to Nortel-derived switch software) to manage VLAN forwarding behavior at the port level. It exposes configuration data about VLAN forwarding table entries, port-to-VLAN membership, VLAN ID lists, tag actions, and tag capability per interface. Its role in monitoring device status is mainly configuration-integrity oriented: polling the forwarding table lets an operator confirm that each interface is actually carrying the VLANs and tag behavior it was configured for, catching misconfigurations before they cause dropped or leaked traffic, rather than reporting hardware faults directly. It depends on standard interface indexing conventions (ifIndex, as in IF-MIB) to tie VLAN forwarding entries to physical/logical ports. It is typically deployed on managed Ethernet switches performing VLAN-based Layer 2 segmentation in enterprise or campus networks. Engineers can download the NBS-VLAN-FWD-MIB file directly to load it into their MIB browser.
IPNetwork Monitor allows you to monitor SNMP objects defined in NBS-VLAN-FWD-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
- Layer 2 managed Ethernet switch
- vendor-neutral/Nortel-derived switching MIB, not tied to one specific manufacturer
Monitoring Examples
An administrator would poll nbsVlanFwdTable/nbsVlanFwdEntry indexed by nbsVlanFwdIfIndex to see which VLAN IDs (nbsVlanFwdVidList, nbsVlanFwdVid) are forwarded on a given port, plus nbsVlanFwdEgressTagAction and nbsVlanFwdIngressTagAction to confirm whether frames are tagged or untagged at each direction. A mismatch between the expected VLAN list and what a port is actually forwarding would reveal a trunking misconfiguration causing traffic loss or VLAN leakage. nbsVlanFwdTableSize and nbsVlanControlTableSize give visibility into current forwarding-table usage versus device capacity.
What Can Be Monitored
- VLAN forwarding table entries per port
- VLAN ID list per interface
- egress/ingress tag action
- tag capability per port
- forwarding table size vs. capacity
- port VLAN priority
Imported Objects
From NBS-CMMC-MIB
| InterfaceIndex | |
| nbs | OBJECT-IDENTITY |
From SNMPv2-SMI
| MODULE-IDENTITY | |
| OBJECT-IDENTITY | |
| OBJECT-TYPE | |
| Unsigned32 |
From SNMPv2-TC
| DisplayString |
OIDs
RFC description
NBS MIB for managing VLAN forwarding configuration and VLAN control capabilities on network devices.
Start monitoring Layer 2 managed Ethernet switch (Nortel-derived VLAN forwarding) 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.