All MIBs › USR-INVERSEARP-MIB
Organization: 3Com Corporation, Carrier Division
Last Updated: 2000-01-14
Category: CommWorks/3Com Access Equipment
Description: Manages Inverse ARP protocol configuration for Frame Relay on 3Com Carrier Division equipment.
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What Is USR-INVERSEARP-MIB?
USR-INVERSEARP-MIB is a proprietary 3Com Carrier Division MIB governing Inverse ARP, the protocol Frame Relay devices use to automatically resolve a remote DLCI's network-layer address. It exposes a table mapping each Frame Relay virtual circuit's physical/DLCI address to the discovered network address, along with entry age, protocol type, and control objects for the Inverse ARP process (transmit interval, max age, cache-clear command, and per-interface status). Its monitoring value is software/protocol status: confirming that address resolution over Frame Relay circuits is succeeding and current, and that stale entries are being aged out appropriately, rather than physical hardware health. It is closely tied to Frame Relay management (complementing a module like USR-FR-MIB) and to the general ARP/Inverse ARP concepts standardized in RFC 2390. It is typically deployed on 3Com/CommWorks Frame Relay-capable routers and access concentrators in WAN environments using dynamic DLCI-to-address resolution. Engineers can download the USR-INVERSEARP-MIB file directly to load it into their MIB browser.
IPNetwork Monitor allows you to monitor SNMP objects defined in USR-INVERSEARP-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
- 3Com Carrier Division (CommWorks) Frame Relay router/access equipment
Monitoring Examples
An admin would walk usrInverseARPTable (usrInverseARPEntry rows keyed by usrInverseARPIfIndex and usrInverseARPPhysAddress) to see the resolved usrInverseARPNetAddress and usrInverseARPType for each Frame Relay circuit, along with usrInverseARPAge to check how recently the mapping was learned. If a circuit's entry never appears or usrInverseARPStatus shows it invalid, that signals an Inverse ARP resolution failure on that DLCI; usrInverseARPTxInterval and usrInverseARPMaxAge control how aggressively the device re-resolves and expires entries, and usrInverseARPCacheClear can be invoked to force a fresh resolution.
What Can Be Monitored
- resolved DLCI-to-network-address mappings
- Inverse ARP entry age
- Inverse ARP entry status/validity
- transmit interval and max-age settings
- cache-clear control state
Imported Objects
From RFC1155-SMI
| IpAddress |
From SNMPv2-SMI
| Integer32 | |
| MODULE-IDENTITY | |
| OBJECT-TYPE |
From SNMPv2-TC
| RowStatus |
From USR-DEFINITIONS-MIB
| PhysAddress | |
| common | OBJECT-IDENTITY |
OIDs
RFC description
Manages Inverse ARP mappings between IP addresses and DLCI-interface pairs for Frame Relay networks.
Start monitoring 3Com Carrier Division (CommWorks) Frame Relay router/access equipment (Inverse ARP resolution/aging 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.