{"id":395127,"date":"2024-12-18T14:49:03","date_gmt":"2024-12-18T14:49:03","guid":{"rendered":"https:\/\/www.ninjaone.com\/?post_type=script_hub&p=395127"},"modified":"2024-12-18T14:49:03","modified_gmt":"2024-12-18T14:49:03","slug":"ueberwachung-von-dhcp-leases","status":"publish","type":"script_hub","link":"https:\/\/www.ninjaone.com\/de\/script-hub\/ueberwachung-von-dhcp-leases\/","title":{"rendered":"Umfassender Guide zur \u00dcberwachung von DHCP-Leases mit PowerShell"},"content":{"rendered":"

M\u00f6chten Sie mehr \u00fcber die Automatisierung von DHCP-Lease-Benachrichtigungen<\/strong> mit PowerShell erfahren? In diesem Artikel wird erl\u00e4utert, warum die \u00dcberwachung und Verwaltung von DHCP-Bereichen eine wichtige Aufgabe f\u00fcr IT-Expert:innen und Managed Service Provider (MSPs)<\/a> ist. Wenn Sie sicherstellen, dass die DHCP-Server effizient funktionieren und gen\u00fcgend IP-Adressen<\/a> im Pool vorhanden sind, k\u00f6nnen Sie Netzwerkprobleme vermeiden und eine nahtlose Konnektivit\u00e4t gew\u00e4hrleisten.<\/p>\n

Im Fokus steht deshalb ein PowerShell-Skript zur \u00dcberwachung von DHCP-Bereichen, das Administratoren benachrichtigt, wenn die Anzahl der verf\u00fcgbaren Leases unter einen bestimmten Schwellenwert f\u00e4llt. Dieses Skript ist ein unverzichtbares Tool f\u00fcr die Aufrechterhaltung der Zuverl\u00e4ssigkeit vom Netzwerk und zur Vermeidung m\u00f6glicher Unterbrechungen.<\/p>\n

Kontext<\/h2>\n

Das Dynamic Host Configuration Protocol (DHCP)<\/a> ist ein Netzwerkverwaltungs-Protokoll, das zur Automatisierung der Konfiguration von Ger\u00e4ten in IP-Netzwerken verwendet wird. Ohne DHCP m\u00fcsste jedem Ger\u00e4t im Netzwerk manuell eine IP-Adresse zugewiesen werden. Angesichts des dynamischen Charakters moderner Netzwerke sind DHCP-Server oft st\u00e4ndig gefordert, IP-Adressen bereitzustellen.<\/p>\n

Es ist essenziell, diese Server zu \u00fcberwachen und daf\u00fcr zu sorgen, dass ausreichende Leases vorhanden sind. Das mitgelieferte PowerShell-Skript erf\u00fcllt diese Anforderung, indem es die DHCP-Bereiche \u00fcberpr\u00fcft und Administratoren benachrichtigt, wenn die Anzahl der freien Leases unter einen bestimmten Schwellenwert f\u00e4llt.<\/p>\n

Das Skript zur \u00dcberwachung von DHCP-Leases<\/h2>\n
#Requires -Version 5.1\r\n\r\n<#\r\n.SYNOPSIS\r\n    Checks the DHCP scopes for the number of leases used and alerts if the threshold is exceeded.\r\n.DESCRIPTION\r\n    Checks the DHCP scopes for the number of leases used and alerts if the threshold is exceeded.\r\n    This script requires the DhcpServer module to be installed with the DHCP server feature installed.\r\n    The script will output the number of leases used, free, and total for each scope.\r\n    If the LeaseThreshold parameter is set, the script will alert if the number of free leases is less than the threshold.\r\n    If the ExcludeScope parameter is set, the script will exclude the specified scope from the output.\r\n    If the IncludeScope parameter is set, the script will only include the specified scope in the output.\r\n\r\n.PARAMETER LeaseThreshold\r\n    The number of free leases that will trigger an alert. If the number of free leases is less than the threshold, an alert will be triggered.\r\n.PARAMETER ExcludeScope\r\n    The name of the scope to exclude from the output.\r\n.PARAMETER IncludeScope\r\n    The name of the scope to include in the output.\r\n\r\n.EXAMPLE\r\n    (No Parameters)\r\n    ## EXAMPLE OUTPUT WITHOUT PARAMS ##\r\n    [Info] Scope: Test1 Leases Used(In Use\/Total): 250\/252\r\n    [Info] Scope: Test2 Leases Used(In Use\/Total): 220\/252\r\n    [Info] Scope: Test6 Leases Used(In Use\/Total): 4954378\/18446744073709551615\r\n\r\n.EXAMPLE\r\n    PARAMETER: -LeaseThreshold 10\r\n    ## EXAMPLE OUTPUT WITH LEASETHRESHOLD ##\r\n    [Alert] Scope: Test1 Leases Used(In Use\/Free\/Total): 220\/2\/252\r\n    [Info] Scope: Test2 Leases Used(In Use\/Free\/Total): 150\/102\/252\r\n    [Info] Scope: Test6 Leases Used(In Use\/Free\/Total): 0\/18446744073709551615\/18446744073709551615\r\n\r\n.EXAMPLE\r\n    PARAMETER: -ExcludeScope \"Test1\"\r\n    ## EXAMPLE OUTPUT WITH EXCLUDESCOPE ##\r\n    [Info] Scope: Test2 Leases Used(In Use\/Free\/Total): 220\/2\/252\r\n    [Info] Scope: Test6 Leases Used(In Use\/Free\/Total): 0\/18446744073709551615\/18446744073709551615\r\n\r\n.EXAMPLE\r\n    PARAMETER: -IncludeScope \"Test2\"\r\n    ## EXAMPLE OUTPUT WITH INCLUDESCOPE ##\r\n    [Info] Scope: Test2 Leases Used(In Use\/Free\/Total): 220\/2\/252\r\n.NOTES\r\n    Minimum OS: Windows Server 2016\r\n    Requires the DhcpServer module to be installed with the DHCP server feature installed.\r\n    Release Notes: Initial Release\r\nBy using this script, you indicate your acceptance of the following legal terms as well as our Terms of Use at https:\/\/www.ninjaone.com\/terms-of-use.\r\n    Ownership Rights: NinjaOne owns and will continue to own all right, title, and interest in and to the script (including the copyright). NinjaOne is giving you a limited license to use the script in accordance with these legal terms. \r\n    Use Limitation: You may only use the script for your legitimate personal or internal business purposes, and you may not share the script with another party. \r\n    Republication Prohibition: Under no circumstances are you permitted to re-publish the script in any script library or website belonging to or under the control of any other software provider. \r\n    Warranty Disclaimer: The script is provided \u201cas is\u201d and \u201cas available\u201d, without warranty of any kind. NinjaOne makes no promise or guarantee that the script will be free from defects or that it will meet your specific needs or expectations. \r\n    Assumption of Risk: Your use of the script is at your own risk. You acknowledge that there are certain inherent risks in using the script, and you understand and assume each of those risks. \r\n    Waiver and Release: You will not hold NinjaOne responsible for any adverse or unintended consequences resulting from your use of the script, and you waive any legal or equitable rights or remedies you may have against NinjaOne relating to your use of the script. \r\n    EULA: If you are a NinjaOne customer, your use of the script is subject to the End User License Agreement applicable to you (EULA).\r\n#>\r\n\r\n[CmdletBinding()]\r\nparam (\r\n    $LeaseThreshold,\r\n    [string[]]$ExcludeScope,\r\n    [string[]]$IncludeScope\r\n)\r\n\r\nbegin {\r\n    function Test-IsElevated {\r\n        # check if running under a Pester test case\r\n        $id = [System.Security.Principal.WindowsIdentity]::GetCurrent()\r\n        $p = New-Object System.Security.Principal.WindowsPrincipal($id)\r\n        $p.IsInRole([System.Security.Principal.WindowsBuiltInRole]::Administrator)\r\n    }\r\n\r\n    try {\r\n        if ($env:leaseThreshold -and $env:leaseThreshold -notlike \"null\") {\r\n            [int]$LeaseThreshold = $env:leaseThreshold\r\n        }\r\n    }\r\n    catch {\r\n        Write-Host \"[Error] LeaseThreshold must be a number\"\r\n        exit 2\r\n    }\r\n    \r\n    if ($env:excludeScope -and $env:excludeScope -notlike \"null\") {\r\n        $ExcludeScope = $env:excludeScope\r\n    }\r\n    if ($env:includeScope -and $env:includeScope -notlike \"null\") {\r\n        $IncludeScope = $env:includeScope\r\n    }\r\n\r\n    # Split the ExcludeScope and IncludeScope parameters into an array\r\n    if (-not [String]::IsNullOrWhiteSpace($ExcludeScope) -and $ExcludeScope -like '*,*') {\r\n        $ExcludeScope = $ExcludeScope -split ',' | ForEach-Object { $_.Trim() } | Where-Object { -not [String]::IsNullOrWhiteSpace($_) } | Sort-Object -Unique\r\n    }\r\n    if (-not [String]::IsNullOrWhiteSpace($IncludeScope) -and $IncludeScope -like '*,*') {\r\n        $IncludeScope = $IncludeScope -split ',' | ForEach-Object { $_.Trim() } | Where-Object { -not [String]::IsNullOrWhiteSpace($_) } | Sort-Object -Unique\r\n    }\r\n\r\n    # Check if $ExcludeScope and $IncludeScope contain similar items\r\n    if (-not [String]::IsNullOrWhiteSpace($ExcludeScope) -and -not [String]::IsNullOrWhiteSpace($IncludeScope)) {\r\n        $SimilarItems = $ExcludeScope | Where-Object { $IncludeScope -contains $_ }\r\n        if ($SimilarItems) {\r\n            Write-Host \"[Error] The following scopes are in both ExcludeScope and IncludeScope: $($SimilarItems -join ', ')\"\r\n            exit 2\r\n        }\r\n    }\r\n\r\n    $ShouldAlert = $false\r\n}\r\nprocess {\r\n    if (-not (Test-IsElevated)) {\r\n        Write-Host \"[Error] Access Denied. Please run with Administrator privileges.\"\r\n        exit 2\r\n    }\r\n\r\n    # Check if the DhcpServer module is installed\r\n    if (-not (Get-Module -ListAvailable -Name DhcpServer -ErrorAction SilentlyContinue)) {\r\n        Write-Host \"[Error] The DhcpServer module is not installed. Please install the DHCP server feature and the DhcpServer module.\"\r\n        exit 2\r\n    }\r\n\r\n    # Get all DHCP scopes\r\n    $AllScopes = $(\r\n        Get-DhcpServerv4Scope | Select-Object -ExpandProperty Name\r\n        Get-DhcpServerv6Scope | Select-Object -ExpandProperty Name\r\n    )\r\n\r\n    # Output an error if the ExcludeScope or IncludeScope parameters contain invalid scope names\r\n    $(\r\n        if ($IncludeScope) { $IncludeScope }\r\n        if ($ExcludeScope) { $ExcludeScope }\r\n    ) | ForEach-Object {\r\n        if ($_ -notin $AllScopes) {\r\n            Write-Host \"[Error] Scope: $_ does not exist in the DHCP server. Please check the scope name and try again.\"\r\n        }\r\n    }\r\n\r\n    # IPv4\r\n    # Get all DHCP scopes\r\n    $v4scopes = Get-DhcpServerv4Scope | Where-Object { $_.State }\r\n\r\n    # Iterate through each scope\r\n    foreach ($scope in $v4scopes) {\r\n        # Get statistics for the scope\r\n        $Stats = Get-DhcpServerv4ScopeStatistics -ScopeId $scope.ScopeId\r\n\r\n        # Get the name of the scope\r\n        $Name = (Get-DhcpServerv4Scope -ScopeId $scope.ScopeId).Name\r\n\r\n        # Check if the scope should be excluded\r\n        if (-not [String]::IsNullOrWhiteSpace($ExcludeScope) -and $Name -in $ExcludeScope) {\r\n            continue\r\n        }\r\n\r\n        # Check if the scope should be included\r\n        if (-not [String]::IsNullOrWhiteSpace($IncludeScope) -and $Name -notin $IncludeScope) {\r\n            continue\r\n        }\r\n\r\n        # Check if the number of free leases is less than the threshold\r\n        if ($Stats.Free -lt $LeaseThreshold ) {\r\n            if ($ShouldAlert -eq $false) {\r\n                # Output once if this is the first scope to trigger an alert\r\n                Write-Host \"[Alert] Available DHCP Leases Low. You may want to make modifications to one of the below scopes.\"\r\n            }\r\n            Write-Host \"[Alert] Scope: $Name Leases Used(In Use\/Free\/Total): $($Stats.InUse)\/$($Stats.Free)\/$($Stats.InUse+$Stats.Free)\"\r\n            $ShouldAlert = $true\r\n        }\r\n        else {\r\n            Write-Host \"[Info] Scope: $Name Leases Used(In Use\/Free\/Total): $($Stats.InUse)\/$($Stats.Free)\/$($Stats.InUse+$Stats.Free)\"\r\n        }\r\n    }\r\n\r\n    # IPv6\r\n    # Get all DHCP scopes\r\n    $v6Scopes = Get-DhcpServerv6Scope | Where-Object { $_.State }\r\n\r\n    # Iterate through each scope\r\n    foreach ($scope in $v6Scopes) {\r\n        # Get statistics for the scope\r\n        $Stats = Get-DhcpServerv6ScopeStatistics -Prefix $scope.Prefix\r\n\r\n        # Get the name of the scope\r\n        $Name = (Get-DhcpServerv6Scope -Prefix $scope.Prefix).Name\r\n\r\n        # Check if the scope should be excluded\r\n        if (-not [String]::IsNullOrWhiteSpace($ExcludeScope) -and $Name -in $ExcludeScope) {\r\n            continue\r\n        }\r\n\r\n        # Check if the scope should be included\r\n        if (-not [String]::IsNullOrWhiteSpace($IncludeScope) -and $Name -notin $IncludeScope) {\r\n            continue\r\n        }\r\n\r\n        # Check if the number of free leases is less than the threshold\r\n        if ($Stats.Free -lt $LeaseThreshold ) {\r\n            if ($ShouldAlert -eq $false) {\r\n                # Output once if this is the first scope to trigger an alert\r\n                Write-Host \"[Alert] Available DHCP Leases Low. You may want to make modifications to one of the below scopes.\"\r\n            }\r\n            Write-Host \"[Alert] Scope: $Name Leases Used(In Use\/Free\/Total): $($Stats.InUse)\/$($Stats.Free)\/$($Stats.InUse+$Stats.Free)\"\r\n            $ShouldAlert = $true\r\n        }\r\n        else {\r\n            Write-Host \"[Info] Scope: $Name Leases Used(In Use\/Free\/Total): $($Stats.InUse)\/$($Stats.Free)\/$($Stats.InUse+$Stats.Free)\"\r\n        }\r\n    }\r\n\r\n    exit 0\r\n\r\n}\r\nend {\r\n    \r\n    \r\n    \r\n}<\/pre>\n
 <\/p>\n\n
Detailansicht<\/h2>\n
Dieses PowerShell-Skript erfordert das DhcpServer-Modul und ist mit Windows Server 2016 oder h\u00f6her kompatibel. Im Folgenden wird Schritt f\u00fcr Schritt erkl\u00e4rt, wie es funktioniert:<\/p>\n
Parameter<\/h2>\n