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 1.2.0:

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 released under the MIT License.

Copyright © 2004-2014 David R. Halliday

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the “Software”), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED “AS IS”, WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.