MIB Viewer

MIB Viewer is a free SNMP MIB browser and database with over 12,000 MIBs and 1,600,000 OIDs, covering both the standard, cross-vendor MIBs every device supports and the enterprise-specific MIBs published by individual hardware vendors. Search by name, OID, or number to look up any MIB object, view its syntax, access level, and description, trace its place in the MIB tree, and generate ready-to-run SNMP commands — all in your browser, with nothing to install and no account required. The database grows continuously, and beyond the lookup tool itself, the site includes a growing library of written guides and reference material covering SNMP concepts, vendor-specific configuration, DOCSIS cable modem and CMTS monitoring, and troubleshooting — see the Guides menu above, or the highlights below.

What's a MIB?

A MIB (Management Information Base) defines the data a device can report over SNMP — things like interface counters, system uptime, or CPU load — organizing each value under a name and a fixed numeric address. Every MIB module declares a tree of related objects, and a device typically implements dozens of MIBs at once: a handful of universal ones every vendor supports, plus whatever proprietary ones that specific vendor has published.

What's SNMP?

SNMP (Simple Network Management Protocol) is how routers, switches, servers, and other network devices report status and statistics back to monitoring tools. It's the transport; MIBs are the vocabulary that gives the data it carries any meaning. Most monitoring platforms — Zabbix, PRTG, LibreNMS, Prometheus's SNMP exporter, and plenty of others — rely on this same underlying protocol and MIB structure.

What's an OID?

An OID is the actual address of one piece of data — a dotted sequence like 1.3.6.1.2.1.1.1, read from the root of a shared global tree down to one specific object. Names are for humans; OIDs are what actually gets sent over the wire. Every vendor's private MIBs live under that vendor's own reserved branch of the same tree, which is what lets one numbering system cover both universal and proprietary data.

Try it: sysDescr (1.3.6.1.2.1.1.1) → Read more →

Guides & Resources

Beyond the lookup tool, the site includes practical, hands-on guides and reference material — installing and using the standard SNMP tools, configuring SNMP on specific vendor hardware, monitoring DOCSIS cable modems and CMTSs, and working through the errors people run into most. A few places to start:

SNMP Fundamentals

The manager/agent model, MIBs and OIDs, versions, access control, and all six core operations in one place.

Using net-snmp

Installing the standard Linux SNMP toolkit, the client commands, running an agent, receiving traps, and loading MIBs into each one.

Configuring SNMP on Cisco devices

Community strings, SNMPv3 users, and trap destinations across classic IOS, IOS-XE, and NX-OS — including where NX-OS's syntax genuinely diverges.

Configuring SNMP on Fortinet devices

FortiOS's config system snmp syntax for communities, SNMPv3 users, and choosing which events actually generate a trap.

Understanding MIBs

How objects, tables, and notifications are actually defined, and how vendor-specific numbering keeps everyone's private OIDs from colliding.

Troubleshooting SNMP

From a plain timeout to SNMPv3 auth failures to a MIB that won't parse — working through what actually went wrong and why.

Searching OIDs

Starting from a real device's sysObjectID, searching by name or number, and filtering a MIB down to just the objects you need.

Modem/MTA bootfiles

Compiling modem and MTA configuration files from plain text, and reading real Arris and Hitron examples OID by OID.

DOCSIS Monitoring

Signal quality and status OIDs for both the modem and CMTS side, what changed across DOCSIS versions, and how DOCS-IF3/IF31-MIB extend it for bonded and OFDM channels.

Linux snmpd passthrough

NET-SNMP-EXTEND-MIB and the extend directive in snmpd.conf, used to expose the output of shell scripts as custom OIDs.

Get started

Search for a MIB or OID above, or pick one from the list on the left.

Have your own MIB file? Drop it on the upload zone in the sidebar (or click to browse) to parse and explore it right away. It's sent to the server to be parsed and isn't added to the shared, publicly searchable database — it stays scoped to your own session in the tree on the left.

New here? The Guides menu above is the place to start if you want the concepts explained rather than just looked up.

iso/org/dod/internet/private/enterprises/.81/.12/.6/.1/fethPortTable/fethPortEntry/fethPortSymbolErrors

fethPortSymbolErrors

OBJECT-TYPE

1.3.6.1.4.1.81.12.6.1.1.1.25

Access

read-only

Status

mandatory

Source

MODULES-MIB

Sub-identifiers

Description

This counter is incremented by one each time when valid length packet was received at the port and there was at least one occurrence of an invalid data symbol. This can increment only once per valid carrier event. A collision presence at any port of the repeater containing port N, will not cause this attribute to increment. This Counter has a maximum increment rate of 160,000 counts per second for 100Mb/s implementation. REFERENCE Reference IEEE Draft Std 802.3u/D4 Rptr Mgt, 30.4.3.1.17, aSymbolErrorDuringPacket. Reference IETF 100Base-T Repeater MIB, rptr100MonitorPortSymbolErrors.

Syntax

Counter

Bulk Translate

Paste in text that contains SNMP OIDs — snmpwalk output, a log file, anything — and Translate will find every OID in it and resolve each one to its full MIB-NAME::objectName.instance name.

Search Vendor MIBs

Search by vendor name (for example juniper) to list every MIB defined under that vendor’s IANA enterprise numbers. A vendor that holds several enterprise numbers, is searched under all of them. A number such as 2636 also works.

Search Vendor Traps

Search by vendor name (for example juniper) to list every SNMP notification (trap) defined under that vendor’s IANA enterprise numbers. Both SNMPv2 NOTIFICATION-TYPE and SNMPv1 TRAP-TYPE definitions are included. A number such as 2636 also works.