Exception calling "Get" with "1" argument(s): "WinSNMP API Error: For internal/undefined errors"
At line:1 char:10
+ $SNMP.Get <<<< (".1.3.6.1.2.1.1.5.0")
+ CategoryInfo : NotSpecified: (:) [], MethodInvocationException
+ FullyQualifiedErrorId : ComMethodTargetInvocation
Alternatively, I've been using a command-line (CLI) tool with PowerShell and capturing the output. Since there are a few old CLI tools for SNMP that are free, like snmpget.exe and snmpset.exe by snmpsoft (dot) com. I've been using this for my SNMP get and set routines to control my home brewed SCADA system for nearly a year now with no issue.
So, where do we get started?
You can capture any output from a CLI tool fairly easily. Just run the program inside of a PowerShell variable value, as such:
$output = mycli.exe
That seems simple enough. Next, you need to ensure that you capture all of your CLI tool's output - or at least I prefer to - including any errors which sometimes sneak by. about_Redirection describes that 2>&1 at the end of your CLI tool will capture your success output along with any error output. You can also include all output with *>&1 - to each their own, but I prefer just errors and success output.
$output = mycli.exe 2>&1
Wrap it all tight in a few functions and you just saved some dollars... on SNMP get and set funcitons.
PowerShell get-snmp function
<#
.SYNOPSIS
Function to capture output from snmpget exe CLI tool.
.DESCRIPTION
Based on the parameters sent, the CLI tool will be triggered and the output will be returned based on the output.
.NOTES
Author : Justin Bennett
Date : 2015-03-10
Contact : http://www.allthingstechie.net
Revision : v1.01
Changes : v1.01 - Changed Write-Error to Throw
.PARAMETER ip
IP Address or Hostname
.PARAMETER ver
SNMP Version
.PARAMETER community
SNMP Community String to read the OID
.PARAMETER OID
SNMP OID to read
.PARAMETER returntype
Specify the preferred return type - gauge32, integer, string (Default), timeticks, or todate
.EXAMPLE
C:\PS> get-snmp -ip "192.168.0.10" -ver "1" -community "public" -oid "1.3.6.1.2.1.1.5.0"
sysLocation-Example
.EXAMPLE
C:\PS> #Get SNMP Contact Info
C:\PS> $oid = "1.3.6.1.2.1.1.4.0", "1.3.6.1.2.1.1.5.0", "1.3.6.1.2.1.1.6.0"
C:\PS> $oid | % { get-snmp -ip "192.168.0.10" -ver "1" -community "public" -oid $_ }
sysName-Example
sysLocation-Example
sysServices-Example
#>
function get-snmp {
[CmdletBinding()]
param (
[parameter(Mandatory = $true)] [string]$ip,
[parameter(Mandatory = $true)] [string]$ver,
[parameter(Mandatory = $true)] [string]$community,
[parameter(Mandatory = $true)] [string]$oid,
[parameter(Mandatory = $false)] [ValidateSet("timeticks","integer","gauge32","string","todate")] [string]$returntype = "string"
)
#location of the snmpget program
$snmpdir = ".\"
$output = (. $snmpdir\snmpget.exe -v:$ver -c:"$community" -r:$ip -o:$oid 2>&1) | select -skip 3
$outputsplit = $output -split "="
if ($outputsplit[0].tolower() -ne "oid") {
#one more try
$output = (. $snmpdir\snmpget.exe -v:$ver -c:"$community" -r:$ip -o:$oid 2>&1) | select -skip 3
$outputsplit = $output -split "="
}
switch ($outputsplit[0].tolower()) {
"oid" {
if($returntype -eq $null) { $returntype = $outputsplit[3] }
switch ($returntype.tolower()) {
"timeticks" {
$time = ($outputsplit[5]) -replace "\.", ":" -split ":"
return New-TimeSpan -hour $time[0] -min $time[1]
}
"integer" {
return [int]$outputsplit[5]
}
"gauge32" {
return [int]$outputsplit[5]
}
"string" {
return [string]$outputsplit[5]
}
"todate" {
return [datetime](get-date (($outputsplit[5]) -replace "`"",""))
}
default{
return $outputsplit[5]
}
}
}
default {
throw $output
}
}
}
 |
| Example Output |
Cheers. Even more pieces to the puzzle coming soon.
