Public/Get-specArpEntry.ps1
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function Get-specArpEntry { <# .SYNOPSIS Retrieves the ARP entry for a specified IP address and interface index. .DESCRIPTION This function retrieves the ARP entry for a specific IP address on a given network interface. It queries the system's ARP cache using `Get-NetNeighbor` and returns the ARP entry, if it exists. If the ARP entry cannot be found, a warning is displayed. .PARAMETER IpAddress The IP address for which the ARP entry is to be retrieved. This is a mandatory parameter and supports pipeline input. The IP address should be in the format "x.x.x.x", where x is a number between 0 and 255. .PARAMETER InterfaceIndex The network interface index for which the ARP entry is to be retrieved. This is a mandatory parameter and supports pipeline input. .PARAMETER MacAddress The MAC address to match against. This is an optional parameter. If not provided, the function will return ARP entries for the given IP and interface index, regardless of the MAC address. .EXAMPLE Get-specArpEntry -IpAddress '192.168.1.112' -InterfaceIndex 14 This example retrieves the ARP entry for IP address 192.168.1.112 on Interface Index 14. .EXAMPLE '192.168.1.112' | Get-specArpEntry -InterfaceIndex 14 This example demonstrates using pipeline input to retrieve the ARP entry for a specific IP address on Interface Index 14. .NOTES Author: owen.heaume Version: 1.0 - Initial release 1.1 - Add LinkLayerAddress to ensure check is made against specific MAC 1.2 - Add custom object to return only the relevant properties - Make MacAddress parameter optional #> [CmdletBinding()] param( [Parameter(Mandatory = $true, ValueFromPipeline = $true, ValueFromPipelineByPropertyName = $true)] [ValidatePattern('^((25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.){3}(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)$')] [string]$IpAddress, [Parameter(Mandatory = $true, ValueFromPipeline = $true, ValueFromPipelineByPropertyName = $true)] [int]$InterfaceIndex, [Parameter(Mandatory = $false, ValueFromPipeline = $true, ValueFromPipelineByPropertyName = $true)] [string]$MacAddress ) process { try { # If MacAddress is provided, filter by MAC address as well, otherwise don't filter by MAC address if ($MacAddress) { $result = Get-NetNeighbor -IPAddress $IpAddress -InterfaceIndex $InterfaceIndex -LinkLayerAddress $MacAddress -ea stop } else { $result = Get-NetNeighbor -IPAddress $IpAddress -InterfaceIndex $InterfaceIndex -ea stop } if ($result) { [pscustomobject]@{ IPAddress = $result.IPAddress LinkLayerAddress = $result.LinkLayerAddress State = $result.State InterfaceIndex = $result.ifIndex } } else { Write-Verbose "No ARP entry found for IP $IpAddress on Interface Index $InterfaceIndex" return $null } } catch { Write-Verbose "Error retrieving ARP entry for IP $IpAddress on Interface Index $InterfaceIndex" return $null } } } |