Adding DHCP reservations with PowerShell

martinpeverley · 2021-07-13T17:32:50.000Z

I’m following Microsoft’s site for adding DHCP reservations using PowerShell and a CSV file but it’s not working.

I’m running PS as admin on the DHCP server.

If I type the individual PS commands to add reservations one at a time, it works.

There’s no error given, just doesn’t work. In the PowerShell Operational log it does show an EventID 4104

Neally · 2021-07-13T17:37:05.000Z

Limey:

but it’s not working

Can you give more info? what you provided is not really helpful.

provide the code you are running [ we can’t read minds ;¬) ]
provide the EXACT format of your CSV file, as that’s important to know for the Powershell code
provide the error or details about what exactly is not working or not working as expected
provide the article you are following so we know what you are talking about
optionally provide OS and powershell version used

If you post code, please use the ‘Insert Code’ button. Please and thank you!

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Neally · 2021-07-13T17:41:33.000Z

I assume the code is something like so:
with that you have to make sure the CSv has the right format i.e. have a scopeid, ipaddress, clietid and description column

$csv = Import-Csv "Reservations.csv" 

foreach($row in $csv){
    $reservation = @{
        ScopeID     = $row.scopeID
        IPAddress   = $row.ipaddress
        ClientID    = $row.clientID
        Description = $row.description 
    }

    Add-DhcpServerv4Reservation @reservation
}

martinpeverley · 2021-07-13T17:49:20.000Z

Sorry, rushing trying to get this posted before someone else interrupts me, and I have to sanitise some of the code.

Microsoft’s site: Add-DhcpServerv4Reservation (DhcpServer) | Microsoft Learn

My command:

Import-Csv -Path c:\TempPath\IPres.csv | Add-DhcpServerv4Reservation -ComputerName DHCPServerName

My CSV file follows the layout prescribed in the link:

ScopeId,IPAddress,Name,ClientId,Description 10.10.10.0,10.10.10.10,Phone1,1a-1b-1c-1d-1e-1f,Ext 1000 Firstname Lastname 20.20.20.0,20.20.20.11,Computer2,2a-2b-2c-2d-2e-2f,Ext 1001 Firstname Lastname

If I type the commands into PowerShell, e.g. as follows, then it works.

Add-DhcpServerv4Reservation -ScopeId 10.10.10.0 -IPAddress 10.10.10.8 -ClientId "F0-DE-F1-7A-00-5E" -Description "Reservation for Printer"

There are no errors given but the reservations are not added.

Huw3481 · 2021-07-13T17:49:22.000Z

Neally:

Limey:

but it’s not working

Can you give more info? what you provided is not really helpful.

provide the code you are running [ we can’t read minds ;¬) ]

provide the EXACT format of your CSV file, as that’s important to know for the Powershell code

provide the error or details about what exactly is not working or not working as expected

provide the article you are following so we know what you are talking about

optionally provide OS and powershell version used

If you post code, please use the ‘Insert Code’ button. Please and thank you!

PLEASE READ BEFORE POSTING! Read if you're new to the PowerShell forum!

You deserve a gazillion points for calling out a long term spicehead for not actually giving relevant info and doing the whole “Grandmother, egg, suck” routine

Neally · 2021-07-13T17:57:30.000Z

From what you posted, it looks like your CSV file might be off?

if you run this, does everything look ok?

import-csv "C:\YourInputFile.csv"

Look at the code example I posted above, and try it like so

e,g,

$csv = Import-Csv "c:\TempPath\IPres.csv" 

foreach($row in $csv){

    $reservation = @{
        ScopeID     = $row.scopeID
        IPAddress   = $row.ipaddress
        ClientID    = $row.clientID
        Description = $row.description 
    }

    try{
        Add-DhcpServerv4Reservation @reservation -Verbose -ErrorAction Stop
    }
    catch{
        $Error[0].exception.message
    }
}

martinpeverley · 2021-07-13T18:04:55.000Z

If I run your first command ( import-csv “C:\YourInputFile.csv” ) nothing happens.

I had tried your version and nothing happened either, and tried again with the error coding and nothing is returned.

r0b · 2021-07-13T18:36:16.000Z

Have you tried turning it off and going down the pub instead?

Neally · 2021-07-13T19:16:55.000Z

Limey:

If I run your first command ( import-csv “C:\YourInputFile.csv” ) nothing happens.

That’s an issue. Is the path right? Double check and make sure the CSV is a good correct format.

ScopeId,IPAddress,Name,ClientId,Description
10.10.10.0,10.10.10.10,Phone1,1a-1b-1c-1d-1e-1f,Ext 1000 Firstname Lastname
20.20.20.0,20.20.20.11,Computer2,2a-2b-2c-2d-2e-2f,Ext 1001 Firstname Lastname

IT needs the headers and the values are separated by comma.

You need the import-csv part to work ok first, then we can go from there.

philsterz · 2021-07-14T04:02:26.000Z

Hi, Since you have created the .csv file and added the required details.

You can just run this command to import .csv and create DHCP reservations.

Example code:

Import-Csv “Insert path of csv file” | Add-DhcpServerv4Reservation

The above code will add all the rows listed in your .csv file.

If you don’t want to see errors, then add -erroraction silentlycontinue at the end of the code

martinpeverley · 2021-07-14T11:39:54.000Z

Neally:

Double check and make sure the CSV is a good correct format.

Thank you Microsoft for showing me a format like so:

ScopeId,IPAddress,Name,ClientId,Description 10.10.10.0,10.10.10.10,Computer1,1a-1b-1c-1d-1e-1f,Reserved for Computer1 20.20.20.0,20.20.20.11,Computer2,2a-2b-2c-2d-2e-2f,Reserved for Computer2 30.30.30.0,30.30.30.12,Computer3,3a-3b-3c-3d-3e-3f,Reserved for Computer3

Even though each entry should be on it’s own line, like this:

ScopeId,IPAddress,Name,ClientId,Description
10.10.10.0,10.10.10.10,Computer1,1a-1b-1c-1d-1e-1f,Reserved for Computer1
20.20.20.0,20.20.20.11,Computer2,2a-2b-2c-2d-2e-2f,Reserved for Computer2
30.30.30.0,30.30.30.12,Computer3,3a-3b-3c-3d-3e-3f,Reserved for Computer3

FFS, something so simple.

Thanks for the help, I was just going about to give up this morning because even the “Import-Csv” wasn’t showing anything, so I checked on that and this jumped out at me " Each column in the CSV file becomes a property of the custom object and the items in rows become the property values."

Cue the headslap and much rejoicing.

martinpeverley · 2021-09-13T17:13:40.000Z

In the spirit of giving back, or because it pissed me off, I did open a GitHub change request for the documentation being incorrect. Just received notification today that they have fixed it, so “Yay!”