functions/Resolve-DbaNetworkName.ps1
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function Resolve-DbaNetworkName { <# .SYNOPSIS Returns information about the network connection of the target computer including NetBIOS name, IP Address, domain name and fully qualified domain name (FQDN). .DESCRIPTION Retrieves the IPAddress, ComputerName from one computer. The object can be used to take action against its name or IPAddress. First ICMP is used to test the connection, and get the connected IPAddress. Multiple protocols (e.g. WMI, CIM, etc) are attempted before giving up. Important: Remember that FQDN doesn't always match "ComputerName dot Domain" as AD intends. There are network setup (google "disjoint domain") where AD and DNS do not match. "Full computer name" (as reported by sysdm.cpl) is the only match between the two, and it matches the "DNSHostName" property of the computer object stored in AD. This means that the notation of FQDN that matches "ComputerName dot Domain" is incorrect in those scenarios. In other words, the "suffix" of the FQDN CAN be different from the AD Domain. This cmdlet has been providing good results since its inception but for lack of useful names some doubts may arise. Let this clear the doubts: - InputName: whatever has been passed in - ComputerName: hostname only - IPAddress: IP Address - DNSHostName: hostname only, coming strictly from DNS (as reported from the calling computer) - DNSDomain: domain only, coming strictly from DNS (as reported from the calling computer) - Domain: domain only, coming strictly from AD (i.e. the domain the ComputerName is joined to) - DNSHostEntry: Fully name as returned by DNS [System.Net.Dns]::GetHostEntry - FQDN: "legacy" notation of ComputerName "dot" Domain (coming from AD) - FullComputerName: Full name as configured from within the Computer (i.e. the only secure match between AD and DNS) So, if you need to use something, go with FullComputerName, always, as it is the most correct in every scenario. .PARAMETER ComputerName The target SQL Server instance or instances. This can be the name of a computer, a SMO object, an IP address or a SQL Instance. .PARAMETER Credential Login to the target instance using alternative credentials. Accepts PowerShell credentials (Get-Credential). Windows Authentication, SQL Server Authentication, Active Directory - Password, and Active Directory - Integrated are all supported. For MFA support, please use Connect-DbaInstance. .PARAMETER Turbo Resolves without accessing the server itself. Faster but may be less accurate because it relies on DNS only, so it may fail spectacularly for disjoin-domain setups. Also, everyone has its own DNS (i.e. results may vary changing the computer where the function runs) .PARAMETER EnableException By default, when something goes wrong we try to catch it, interpret it and give you a friendly warning message. This avoids overwhelming you with "sea of red" exceptions, but is inconvenient because it basically disables advanced scripting. Using this switch turns this "nice by default" feature off and enables you to catch exceptions with your own try/catch. .NOTES Tags: Network, Resolve Author: Klaas Vandenberghe (@PowerDBAKlaas) | Simone Bizzotto (@niphold) Website: https://dbatools.io Copyright: (c) 2018 by dbatools, licensed under MIT License: MIT https://opensource.org/licenses/MIT .LINK https://dbatools.io/Resolve-DbaNetworkName .EXAMPLE PS C:\> Resolve-DbaNetworkName -ComputerName sql2014 Returns a custom object displaying InputName, ComputerName, IPAddress, DNSHostName, DNSDomain, Domain, DNSHostEntry, FQDN, DNSHostEntry for sql2014 .EXAMPLE PS C:\> Resolve-DbaNetworkName -ComputerName sql2016, sql2014 Returns a custom object displaying InputName, ComputerName, IPAddress, DNSHostName, DNSDomain, Domain, DNSHostEntry, FQDN, DNSHostEntry for sql2016 and sql2014 .EXAMPLE PS C:\> Get-DbaRegServer -SqlInstance sql2014 | Resolve-DbaNetworkName Returns a custom object displaying InputName, ComputerName, IPAddress, DNSHostName, DNSDomain, Domain, DNSHostEntry, FQDN, DNSHostEntry for all SQL Servers returned by Get-DbaRegServer .EXAMPLE PS C:\> Get-DbaRegServer -SqlInstance sql2014, sql2016\sqlexpress | Resolve-DbaNetworkName Returns a custom object displaying InputName, ComputerName, IPAddress, DNSHostName, DNSDomain, Domain, DNSHostEntry, FQDN, DNSHostEntry for all SQL Servers returned by Get-DbaRegServer #> [CmdletBinding()] param ( [parameter(ValueFromPipeline)] [DbaInstanceParameter[]]$ComputerName = $env:COMPUTERNAME, [PSCredential]$Credential, [Alias('FastParrot')] [switch]$Turbo, [switch]$EnableException ) begin { Function Get-ComputerDomainName { Param ( $FQDN, $ComputerName ) # deduce the domain name based on resolved name + original request if ($fqdn -notmatch "\.") { if ($ComputerName -match "\.") { return $ComputerName.Substring($ComputerName.IndexOf(".") + 1) } else { return "$env:USERDNSDOMAIN".ToLowerInvariant() } } else { return $fqdn.Substring($fqdn.IndexOf(".") + 1) } } } process { if ((Get-DbatoolsConfigValue -FullName commands.resolve-dbanetworkname.bypass)) { foreach ($computer in $ComputerName) { [pscustomobject]@{ InputName = $computer ComputerName = $computer IPAddress = $computer DNSHostname = $computer DNSDomain = $computer # (Get-ComputerDomainName -ComputerName $computer) Domain = $computer # (Get-ComputerDomainName -ComputerName $computer) DNSHostEntry = $computer FQDN = $computer FullComputerName = $computer } continue } return } if (-not (Test-Windows -NoWarn)) { Write-Message -Level Verbose -Message "Non-Windows client detected. Turbo (DNS resolution only) set to $true" $Turbo = $true } foreach ($computer in $ComputerName) { if ($computer.IsLocalhost) { $cName = $env:COMPUTERNAME } else { $cName = $computer.ComputerName } # resolve IP address try { Write-Message -Level VeryVerbose -Message "Resolving $cName using .NET.Dns GetHostEntry" $resolved = [System.Net.Dns]::GetHostEntry($cName) $ipaddresses = $resolved.AddressList | Sort-Object -Property AddressFamily # prioritize IPv4 $ipaddress = $ipaddresses[0].IPAddressToString } catch { Stop-Function -Message "DNS name $cName not found" -Continue -ErrorRecord $_ } # try to resolve IP into a hostname try { Write-Message -Level VeryVerbose -Message "Resolving $ipaddress using .NET.Dns GetHostByAddress" $fqdn = [System.Net.Dns]::GetHostByAddress($ipaddress).HostName } catch { Write-Message -Level Debug -Message "Failed to resolve $ipaddress using .NET.Dns GetHostByAddress" $fqdn = $resolved.HostName } $dnsDomain = Get-ComputerDomainName -FQDN $fqdn -ComputerName $cName # augment fqdn if needed if ($fqdn -notmatch "\." -and $dnsDomain) { $fqdn = "$fqdn.$dnsdomain" } $hostname = $fqdn.Split(".")[0] # create an output object with some preliminary data gathered so far $result = [PSCustomObject]@{ InputName = $computer ComputerName = $hostname.ToUpper() IPAddress = $ipaddress DNSHostname = $hostname DNSDomain = $dnsdomain Domain = $dnsdomain DNSHostEntry = $fqdn FQDN = $fqdn FullComputerName = $cName } if ($Turbo) { # that's a finish line for a Turbo mode $result continue } # finding out which IP to use by pinging all of them. The first to respond is the one. $ping = New-Object System.Net.NetworkInformation.Ping $timeout = 1000 #milliseconds foreach ($ip in $ipaddresses) { $reply = $ping.Send($ip, $timeout) if ($reply.Status -eq 'Success') { $ipaddress = $ip.IPAddressToString break } } $result.IPAddress = $ipaddress # re-try DNS reverse zone lookup if the IP to use is not the first one if ($ipaddresses[0].IPAddressToString -ne $ipaddress) { try { Write-Message -Level VeryVerbose -Message "Resolving $ipaddress using .NET.Dns GetHostByAddress" $fqdn = [System.Net.Dns]::GetHostByAddress($ipaddress).HostName # re-adjust DNS domain again $dnsDomain = Get-ComputerDomainName -FQDN $fqdn -ComputerName $cName # augment fqdn if needed if ($fqdn -notmatch "\." -and $dnsDomain) { $fqdn = "$fqdn.$dnsdomain" } $hostname = $fqdn.Split(".")[0] # update result fields accordingly $result.ComputerName = $hostname.ToUpper() $result.DNSHostname = $hostname $result.DNSDomain = $dnsdomain $result.Domain = $dnsdomain $result.DNSHostEntry = $fqdn $result.FQDN = $fqdn } catch { Write-Message -Level VeryVerbose -Message "Failed to obtain a new name from $ipaddress, re-using $fqdn" } } Write-Message -Level Debug -Message "Getting domain name from the remote host $fqdn" try { $ScBlock = { return [System.Net.NetworkInformation.IPGlobalProperties]::GetIPGlobalProperties().DomainName } $cParams = @{ ComputerName = $cName } if ($Credential) { $cParams.Credential = $Credential } $conn = Get-DbaCmObject @cParams -ClassName win32_ComputerSystem -EnableException if ($conn) { # update results accordingly $result.ComputerName = $conn.Name $dnsHostname = $conn.DNSHostname $dnsDomain = $conn.Domain $result.FQDN = "$dnsHostname.$dnsDomain".TrimEnd('.') $result.DNSHostName = $dnsHostname $result.Domain = $dnsDomain } try { Write-Message -Level Debug -Message "Getting DNS domain from the remote host $($cParams.ComputerName)" $dnsSuffix = Invoke-Command2 @cParams -ScriptBlock $ScBlock -ErrorAction Stop -Raw $result.DNSDomain = $dnsSuffix if ($dnsSuffix) { $fullComputerName = $result.DNSHostName + "." + $dnsSuffix } else { $fullComputerName = $result.DNSHostName } $result.FullComputerName = $fullComputerName } catch { Write-Message -Level Verbose -Message "Unable to get DNS domain information from $($cParams.ComputerName)" } } catch { Write-Message -Level Verbose -Message "Unable to get domain name from $($cParams.ComputerName)" } # getting a DNS host entry for the full name try { Write-Message -Level VeryVerbose -Message "Resolving $($result.FullComputerName) using .NET.Dns GetHostEntry" $result.DNSHostEntry = ([System.Net.Dns]::GetHostEntry($result.FullComputerName)).HostName } catch { Write-Message -Level Verbose -Message ".NET.Dns GetHostEntry failed for $($result.FullComputerName)" } # returning the final result $result } } } |