Public/Invoke-SNMPv3Walk.ps1

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function Invoke-SNMPv3Walk
{

<#
 
.SYNOPSIS
 
    Query information from network devices using SNMP GETNEXT 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
 
    GETNEXT requests will start at this object identifier and get all results from the subtree.
    Note that no value will be returned for the provided OID, only from the subtree.
 
.PARAMETER AuthType
 
    Allowed authentication types are None, MD5, SHA1 and SHA256. 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.
 
.INPUTS
 
    None. You cannot pipe objects to SNMPv3Walk.
 
.OUTPUTS
 
    SNMPv3Output
 
.EXAMPLE
 
    PS> Invoke-SNMPv3Walk -UserName usr-none-none -Target demo.snmplabs.com -OID 1.3.6.1.2.1.2.2.1.1 -Context 1016117d6836664ee15b9b2af5642c3c
 
    Node OID Type Value
    ---- --- ---- -----
    104.236.166.95 1.3.6.1.2.1.2.2.1.1.1 Integer32 1
    104.236.166.95 1.3.6.1.2.1.2.2.1.1.2 Integer32 2
    104.236.166.95 1.3.6.1.2.1.2.2.1.1.3 Integer32 3
    104.236.166.95 1.3.6.1.2.1.2.2.1.1.4 Integer32 4
    104.236.166.95 1.3.6.1.2.1.2.2.1.1.5 Integer32 5
 
#>


    [CmdletBinding()]
    [OutputType('SNMPv3Output')]
    param(
        [Parameter(Mandatory=$true)]
        [String]$UserName,

        [Parameter(Mandatory=$true)]
        [String]$Target,

        [Parameter(Mandatory=$true)]
        [String]$OID,

        [Parameter(Mandatory=$false)]
        [SNMPv3AuthType]$AuthType = 'None',

        [Parameter(Mandatory=$false)]
        [String]$AuthSecret,

        [Parameter(Mandatory=$false)]
        [SNMPv3PrivType]$PrivType = 'None',

        [Parameter(Mandatory=$false)]
        [String]$PrivSecret,

        [Parameter(Mandatory=$false)]
        [String]$Context,

        [Parameter(Mandatory=$false)]
        [int]$Port = 161,

        [Parameter(Mandatory=$false)]
        [int]$Timeout = 3000
    )

    $SecurityLevel = Get-SNMPv3SecurityLevel $AuthType $AuthSecret $PrivType $PrivSecret

    if ($SecurityLevel.IsValid)
    {
        $Authentication = Get-SNMPv3AuthenticationProvider $AuthType $AuthSecret
        $Privacy = Get-SNMPv3PrivacyProvider $PrivType $PrivSecret $Authentication
    }
    else
    {
        $InvalidSecurityLevel = [System.FormatException]::new('Invalid security level provided')
        Throw $InvalidSecurityLevel
    }

    $Context = if ([String]::IsNullOrWhiteSpace($Context)) {[String]::Empty} else {$Context}

    $IPAddress = [ipaddress]::None
    if ([ipaddress]::TryParse($Target, [ref]$IPAddress) -eq $false) {
        $IPAddress  = [System.Net.Dns]::GetHostEntry($Target).AddressList[0]
    }

    $IPEndPoint = [System.Net.IPEndPoint]::new($IPAddress, $Port)

    $Discovery = [Lextm.SharpSnmpLib.Messaging.Messenger]::GetNextDiscovery([Lextm.SharpSnmpLib.SnmpType]::GetRequestPdu)
    $Report = $Discovery.GetResponse($Timeout, $IPEndPoint)

    $Result = [System.Collections.Generic.List[Lextm.SharpSnmpLib.Variable]]::new()

    [Lextm.SharpSnmpLib.Messaging.Messenger]::BulkWalk(
        [Lextm.SharpSnmpLib.VersionCode]::V3,
        $IPEndPoint,
        [Lextm.SharpSnmpLib.OctetString]::new($UserName),
        [Lextm.SharpSnmpLib.OctetString]::new($Context),
        [Lextm.SharpSnmpLib.ObjectIdentifier]::new($OID),
        $Result,
        $Timeout,
        10,
        [Lextm.SharpSnmpLib.Messaging.WalkMode]::WithinSubtree,
        $Privacy,
        $Report
    ) | Out-Null

    $Result | foreach {
        [PSCustomObject] @{
            PSTypeName = 'SNMPv3Output'
            Node       = $IPAddress
            OID        = $_.Id.ToString()
            Type       = $_.Data.TypeCode
            Value      = $_.Data
        }
    }
}