Net-SNMP is a suite of software for using and deploying the SNMP

Simple Network Management Protocol

Simple Network Management Protocol is an "Internet-standard protocol for managing devices on IP networks. Devices that typically support SNMP include routers, switches, servers, workstations, printers, modem racks, and more." It is used mostly in network management systems to monitor...

 protocol (v1, v2c and v3 and the AgentX subagent protocol). It supports IPv4

IPv4

Internet Protocol version 4 is the fourth revision in the development of the Internet Protocol and the first version of the protocol to be widely deployed. Together with IPv6, it is at the core of standards-based internetworking methods of the Internet...

, IPv6

IPv6

Internet Protocol version 6 is a version of the Internet Protocol . It is designed to succeed the Internet Protocol version 4...

, IPX

IPX

Internetwork Packet Exchange is the OSI-model Network layer protocol in the IPX/SPX protocol stack.The IPX/SPXM protocol stack is supported by Novell's NetWare network operating system. Because of Netware's popularity through the late 1980s into the mid 1990s, IPX became a popular internetworking...

, AAL5, Unix domain socket

Unix domain socket

A Unix domain socket or IPC socket is a data communications endpoint for exchanging data between processes executing within the same host operating system. While similar in functionality to...

s and other transports. It contains a generic client library, a suite of command line

Command-line interface

A command-line interface is a mechanism for interacting with a computer operating system or software by typing commands to perform specific tasks...

 applications, a highly extensible SNMP agent, perl

Perl

Perl is a high-level, general-purpose, interpreted, dynamic programming language. Perl was originally developed by Larry Wall in 1987 as a general-purpose Unix scripting language to make report processing easier. Since then, it has undergone many changes and revisions and become widely popular...

 modules and python

Python (programming language)

Python is a general-purpose, high-level programming language whose design philosophy emphasizes code readability. Python claims to "[combine] remarkable power with very clear syntax", and its standard library is large and comprehensive...

 modules.

Distribution

Net-SNMP is housed on SourceForge

SourceForge

SourceForge Enterprise Edition is a collaborative revision control and software development management system. It provides a front-end to a range of software development lifecycle services and integrates with a number of free software / open source software applications .While originally itself...

 and is usually in the top 100 projects in the sourceforge ranking system. It was the March 2005 SourceForge Project of the Month.
It is very widely distributed and comes included with many operating systems including most distributions of Linux

Linux

Linux is a Unix-like computer operating system assembled under the model of free and open source software development and distribution. The defining component of any Linux system is the Linux kernel, an operating system kernel first released October 5, 1991 by Linus Torvalds...

, FreeBSD

FreeBSD

FreeBSD is a free Unix-like operating system descended from AT&T UNIX via BSD UNIX. Although for legal reasons FreeBSD cannot be called “UNIX”, as the direct descendant of BSD UNIX , FreeBSD’s internals and system APIs are UNIX-compliant...

, OpenBSD

OpenBSD

OpenBSD is a Unix-like computer operating system descended from Berkeley Software Distribution , a Unix derivative developed at the University of California, Berkeley. It was forked from NetBSD by project leader Theo de Raadt in late 1995...

, Solaris

Solaris Operating System

Solaris is a Unix operating system originally developed by Sun Microsystems. It superseded their earlier SunOS in 1993. Oracle Solaris, as it is now known, has been owned by Oracle Corporation since Oracle's acquisition of Sun in January 2010....

, and Mac OS X

Mac OS X

Mac OS X is a series of Unix-based operating systems and graphical user interfaces developed, marketed, and sold by Apple Inc. Since 2002, has been included with all new Macintosh computer systems...

. It is also available from the Net-SNMP web site.

History

Steve Waldbusser of CMU

Carnegie Mellon University

Carnegie Mellon University is a private research university in Pittsburgh, Pennsylvania, United States....

 started a freely available SNMP tool kit in 1992. The package was later abandoned by CMU and Wes Hardaker at UC Davis

University of California, Davis

The University of California, Davis is a public teaching and research university established in 1905 and located in Davis, California, USA. Spanning over , the campus is the largest within the University of California system and third largest by enrollment...

renamed it to UCD-SNMP and extended it to meet the network management needs of the Electrical Engineering department there. Eventually Mr. Hardaker left the university and realized that the project was now network wide and thus renamed it to Net-SNMP to reflect its distributed development..

The roots of the Net-SNMP project are long and a full description can be found on the Net-SNMP history page.

SNMP Applications Included With Net-SNMP

Application	Description
encode_keychange	produce the KeyChange string for SNMPv3.
snmptranslate	translate MIB OID names between numeric and textual forms.
snmpget	communicates with a network entity using SNMP GET requests.
snmpgetnext	Communicates with a network entity using SNMP GETNEXT requests.
snmpbulkget	Communicates with a network entity using SNMP GETBULK requests.
snmpwalk	retrieve a subtree of management values using SNMP GETNEXT requests.
snmpbulkwalk	retrieve a subtree of management values using SNMP GETBULK requests.
snmpset	communicates with a network entity using SNMP SET requests.
snmptrap	Sends SNMP TRAP or INFORM notification messages.
snmpd	A SNMP agent that responds to SNMP requests for a given host.
snmptrapd	A SNMP demon that listens for SNMP TRAPs or INFORMs and logs or acts upon them.
snmptest	communicates with a network entity using SNMP requests.
mib2c	A MIB conversion utility that can translate MIB structures into other forms, such as C-code
tkmib	a perl/Tk interactive graphical MIB browser for SNMP.

Snmpwalk

The command snmpwalk uses the SNMP GETNEXT request to query a network for a tree of information.

An object identifier (OID) may be given on the command line. This OID specifies which portion of the object identifier space will be searched using GETNEXT requests. All variables in the subtree below the given OID are queried and their values presented to the user. If no OID argument is present, snmpwalk will search the subtree rooted at SNMPv2-SMI::mib-2 (including any MIB object values from other MIB modules, that are defined as lying within this subtree).

Example

An example of snmpwalk usage (this will retrieve all of the variables under the system OID):
$ snmpwalk -t 5 -Os -c demopublic -v 2c test.net-snmp.org system
sysDescr.0 = STRING: Linux test.net-snmp.org 2.6.18-164.el5 #1 SMP Thu Sep 3 03:28:30 EDT 2009 x86_64
sysObjectID.0 = OID: netSnmpAgentOIDs.10
sysUpTimeInstance = Timeticks: (34198503) 3 days, 22:59:45.03
sysContact.0 = STRING: Net-SNMP Coders
sysName.0 = STRING: test.net-snmp.org
sysLocation.0 = STRING: Undisclosed