SNMP Library for Ruby

Summary

This library implements SNMP (the Simple Network Management Protocol). It is implemented in pure Ruby, so there are no dependencies on external libraries like net-snmp. You can run this library anywhere that Ruby can run.

See snmplib.rubyforge.org for more info.

This release supports the following:

See the SNMP::Manager, SNMP::TrapListener, and SNMP::MIB classes and the examples below for more details.

Changes

Changes for version 1.1.1:

Changes for version 1.1.0:

Changes for version 1.0.4:

Changes for version 1.0.3:

Changes for version 1.0.2:

Changes for version 1.0.1:

Changes for version 1.0.0:

Installation

You can use RubyGems [rubygems.org/] to install the latest version of the SNMP library.

gem install snmp

Testing

This library has received limited testing:

I'm very interested in hearing about successes or failures on other platforms.

Send me an email at hallidave at gmail.com.

Examples

Get Request

Retrieve a system description.

require 'snmp'

SNMP::Manager.open(:host => 'localhost') do |manager|
    response = manager.get(["sysDescr.0", "sysName.0"])
    response.each_varbind do |vb|
        puts "#{vb.name.to_s}  #{vb.value.to_s}  #{vb.value.asn1_type}"
    end
end

Set Request

Create a varbind for setting the system name.

require 'snmp'
include SNMP

manager = Manager.new(:host => 'localhost')
varbind = VarBind.new("1.3.6.1.2.1.1.5.0", OctetString.new("My System Name"))
manager.set(varbind)
manager.close

Table Walk

Walk the ifTable.

require 'snmp'

ifTable_columns = ["ifIndex", "ifDescr", "ifInOctets", "ifOutOctets"]
SNMP::Manager.open(:host => 'localhost') do |manager|
    manager.walk(ifTable_columns) do |row|
        row.each { |vb| print "\t#{vb.value}" }
        puts
    end
end

Get-Next Request

A more difficult way to walk the ifTable.

require 'snmp'
include SNMP

Manager.open(:host => 'localhost') do |manager|
    ifTable = ObjectId.new("1.3.6.1.2.1.2.2")
    next_oid = ifTable
    while next_oid.subtree_of?(ifTable)
        response = manager.get_next(next_oid)
        varbind = response.varbind_list.first
        next_oid = varbind.name
        puts varbind.to_s
    end
end

Get-Bulk Request

Get interface description and admin status for 10 rows of the ifTable.

require 'snmp'
include SNMP

ifDescr_OID = ObjectId.new("1.3.6.1.2.1.2.2.1.2")
ifAdminStatus_OID = ObjectId.new("1.3.6.1.2.1.2.2.1.7")
MAX_ROWS = 10
Manager.open(:host => 'localhost') do |manager|
    response = manager.get_bulk(0, MAX_ROWS, [ifDescr_OID, ifAdminStatus_OID])
    list = response.varbind_list
    until list.empty?
        ifDescr = list.shift
        ifAdminStatus = list.shift
        puts "#{ifDescr.value}    #{ifAdminStatus.value}"
    end
end

Trap Handling

Log traps to STDOUT.

require 'snmp'
require 'logger'

log = Logger.new(STDOUT)
m = SNMP::TrapListener.new do |manager|
    manager.on_trap_default do |trap|
        log.info trap.inspect
    end
end
m.join

License

This SNMP Library is Copyright © 2004-2011 by David R. Halliday. It is free software. Redistribution is permitted under the same terms and conditions as the standard Ruby distribution. See the COPYING file in the Ruby distribution for details.