Public/Invoke-SNMPv3Get.ps1
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function Invoke-SNMPv3Get { <# .SYNOPSIS Query information from network devices using SNMP GET requests. .DESCRIPTION Function supports SNMPv3 with security levels noAuthNoPriv, authNoPriv and authPriv. Based on SnmpSharpNet - SNMP Library for C# (http://www.snmpsharpnet.com/) .PARAMETER UserName Username to use when polling information. .PARAMETER Target SNMP Agent you want to get information from. Accepts IP address or host name. .PARAMETER OID Object Identifier to get the value from. .PARAMETER AuthType Allowed authentication types are None, MD5 and SHA1. Defaults to None. .PARAMETER AuthSecret Authentication password used for security level authNoPriv and authPriv. .PARAMETER PrivType Allowed encryption types are None, DES, TripleDES, AES128, AES192 and AES256. Defaults to None. .PARAMETER PrivSecret Encryption password used for security level authPriv. .PARAMETER Context Context to use. For example to request information in the context of a specific vlan. .PARAMETER Port UDP port to use when connecting to the SNMP Agent. Defaults to 161. .PARAMETER Timeout Timeout in milliseconds when connecting to SNMP Agent. Defaults to 3000. .PARAMETER Retry Number of retries if connection fails. Defaults to 1. .EXAMPLE PS> Invoke-SNMPv3Get -UserName usr-none-none -Target demo.snmplabs.com -OID 1.3.6.1.2.1.1.1.0 Node OID Type Value ---- --- ---- ----- 104.236.166.95 1.3.6.1.2.1.1.1.0 OctetString Linux zeus 4.8.6.5-smp #2 SMP Sun Nov 13 14:58:11 CDT 2016 i686 #> [CmdletBinding()] param( [Parameter(Mandatory=$true)] [String]$UserName, [Parameter(Mandatory=$true)] [String]$Target, [Parameter(Mandatory=$true)] [String]$OID, [Parameter(Mandatory=$false)] [ValidateSet('None', 'MD5', 'SHA1')] [String]$AuthType = 'None', [Parameter(Mandatory=$false)] [String]$AuthSecret, [Parameter(Mandatory=$false)] [ValidateSet('None', 'DES', 'TripleDES', 'AES128', 'AES192', 'AES256')] [String]$PrivType = 'None', [Parameter(Mandatory=$false)] [String]$PrivSecret, [Parameter(Mandatory=$false)] [String]$Context, [Parameter(Mandatory=$false)] [int]$Port = 161, [Parameter(Mandatory=$false)] [int]$Timeout = 3000, [Parameter(Mandatory=$false)] [int]$Retry = 1 ) process { $IPAddress = [System.Net.Dns]::GetHostEntry($Target).AddressList[0] $UdpTarget = [SnmpSharpNet.UdpTarget]::new($IPAddress, $Port, $Timeout, $Retry) $Params = [SnmpSharpNet.SecureAgentParameters]::new() if (-not $UdpTarget.Discovery($Params)) { Write-Error 'Discovery failed. Unable to continue...' $UdpTarget.Close() return } if ($AuthType -ne 'None' -and $AuthSecret -and $PrivType -ne 'None' -and $PrivSecret) { Write-Verbose 'Security Level: authPriv' $Params.authPriv($UserName, [SnmpSharpNet.AuthenticationDigests]::$AuthType, $AuthSecret, [SnmpSharpNet.PrivacyProtocols]::$PrivType, $PrivSecret) } elseif ($AuthType -ne 'None' -and $AuthSecret -and $PrivType -eq 'None' -and (-not $PrivSecret)) { Write-Verbose 'Security Level: authNoPriv' $Params.authNoPriv($UserName, [SnmpSharpNet.AuthenticationDigests]::$AuthType, $AuthSecret) } elseif ($AuthType -eq 'None' -and (-not $AuthSecret) -and $PrivType -eq 'None' -and (-not $PrivSecret)) { Write-Verbose 'Security Level: noAuthNoPriv' $Params.noAuthNoPriv($UserName) } else { Write-Error 'Invalid security level. SNMPv3 supports the following security levels: noAuthNoPriv, authNoPriv, authPriv' exit } if ($Context) { $Params.ContextName.Set($Context) } Write-Verbose ('Context: {0}' -f $Params.ContextName) $Pdu = [SnmpSharpNet.Pdu]::new() $Pdu.Type = [SnmpSharpNet.PduType]::Get $Pdu.VbList.Add($OID) Write-Verbose ($Pdu.VbList | foreach {"Variable Binding: $_"}) # Workaround because [SnmpSharpNet.SnmpConstants]::GetTypeName() gives the following error: # The field or property: "EnterpriseSpecific" for type: "SnmpSharpNet.SnmpConstants" differs only in letter casing # from the field or property: "enterpriseSpecific". The type must be Common Language Specification (CLS) compliant. $GetTypeName = [SnmpSharpNet.SnmpConstants].GetMethod("GetTypeName") try { $Result = $UdpTarget.Request($Pdu, $Params) } catch { Write-Warning "$Target`: $_" $Result = $null } if ($Result) { if ($Result.Pdu.Type -eq [SnmpSharpNet.PduType]::Report) { Write-Warning 'Report packet received.' $ErrStr = [SnmpSharpNet.SNMPV3ReportError]::TranslateError($Result) Write-Warning ('Error: {0}' -f $ErrStr) $UdpTarget.Close() return } if ($Result.Pdu.ErrorStatus -ne 0) { $ErrMsg = 'SNMP target has returned error code {0} on index {1}.' -f [SnmpSharpNet.SnmpError]::ErrorMessage($Result.Pdu.ErrorStatus), $Result.Pdu.ErrorIndex Write-Warning $ErrMsg return } foreach ($Vb in $Result.Pdu.VbList) { [PSCustomObject] @{ Node = $IPAddress OID = $Vb.Oid.ToString() Type = $GetTypeName.Invoke($null, $Vb.Value.Type) Value = $Vb.Value.ToString() } } } } } |