PowerShell中Test-NetConnection如何实现分组带表头输出

• 错误提示无法屏蔽：-ErrorAction SilentlyContinue 仅能抑制错误流的输出，Test-NetConnection 连接超时、名称解析失败的提示默认走警告流，不会被这个参数拦截。另外原脚本存在一处语法错误：MP3 443端口测试的Select-Object -后被强制换行，Property参数被拆分到下一行，会直接触发语法报错。同时脚本中使用交互式命令Enter-PSSession时，本地提前定义的服务器地址变量不会自动同步到远程会话，会触发变量未定义的运行错误。
• 表头仅显示一次：PowerShell默认的输出格式化逻辑会自动合并连续输出的同结构对象，统一渲染成一个表格，仅在第一组对象前打印一次表头，后续同结构结果会直接追加行内容，不会重复输出表头。

1. 修复拆分断行的语法错误
2. 给所有Test-NetConnection命令追加-WarningAction SilentlyContinue参数，屏蔽警告流提示
3. 同一测试组的所有测试结果先收集到独立的数组变量中，整组测试完成后统一通过Format-Table输出，强制每组单独渲染表格和表头
4. 替换交互式的Enter-PSSession为脚本可用的Invoke-Command，通过参数传递本地定义的服务器地址变量到远程会话，避免变量未定义错误

修复后的完整脚本如下：

$DP = Read-Host -Prompt 'Input the FQDN for the local DP'
$MP1 = 'MP1'
$MP2 = 'MP2'
$MP3 = 'MP3'
$SUP1 = 'SUP1'
$SUP2 = 'SUP2'
$Client = Read-Host -Prompt 'Input the workstation to test from'

Invoke-Command -ComputerName $Client -ArgumentList $DP,$MP1,$MP2,$MP3,$SUP1,$SUP2 -ScriptBlock {
    param($DP,$MP1,$MP2,$MP3,$SUP1,$SUP2)

    Write-Host 'Testing connectivity to the local distribution point'
    $dpGroup = @()
    $dpGroup += Test-NetConnection -Port 80 $DP -ErrorAction SilentlyContinue -WarningAction SilentlyContinue | Select-Object -Property ComputerName,RemoteAddress,RemotePort,TCPTestSucceeded
    $dpGroup += Test-NetConnection -Port 443 $DP -ErrorAction SilentlyContinue -WarningAction SilentlyContinue | Select-Object -Property ComputerName,RemoteAddress,RemotePort,TCPTestSucceeded
    $dpGroup += Test-NetConnection -Port 8005 $DP -ErrorAction SilentlyContinue -WarningAction SilentlyContinue | Select-Object -Property ComputerName,RemoteAddress,RemotePort,TCPTestSucceeded
    $dpGroup | Format-Table

    Write-Host 'Testing connectivity to the management points'
    $mpGroup = @()
    $mpGroup += Test-NetConnection -Port 10123 $MP1 -ErrorAction SilentlyContinue -WarningAction SilentlyContinue | Select-Object -Property ComputerName,RemoteAddress,RemotePort,TCPTestSucceeded
    $mpGroup += Test-NetConnection -Port 80 $MP1 -ErrorAction SilentlyContinue -WarningAction SilentlyContinue | Select-Object -Property ComputerName,RemoteAddress,RemotePort,TCPTestSucceeded
    $mpGroup += Test-NetConnection -Port 443 $MP1 -ErrorAction SilentlyContinue -WarningAction SilentlyContinue | Select-Object -Property ComputerName,RemoteAddress,RemotePort,TCPTestSucceeded
    $mpGroup += Test-NetConnection -Port 10123 $MP2 -ErrorAction SilentlyContinue -WarningAction SilentlyContinue | Select-Object -Property ComputerName,RemoteAddress,RemotePort,TCPTestSucceeded
    $mpGroup += Test-NetConnection -Port 80 $MP2 -ErrorAction SilentlyContinue -WarningAction SilentlyContinue | Select-Object -Property ComputerName,RemoteAddress,RemotePort,TCPTestSucceeded
    $mpGroup += Test-NetConnection -Port 443 $MP2 -ErrorAction SilentlyContinue -WarningAction SilentlyContinue | Select-Object -Property ComputerName,RemoteAddress,RemotePort,TCPTestSucceeded
    $mpGroup += Test-NetConnection -Port 10123 $MP3 -ErrorAction SilentlyContinue -WarningAction SilentlyContinue | Select-Object -Property ComputerName,RemoteAddress,RemotePort,TCPTestSucceeded
    $mpGroup += Test-NetConnection -Port 80 $MP3 -ErrorAction SilentlyContinue -WarningAction SilentlyContinue | Select-Object -Property ComputerName,RemoteAddress,RemotePort,TCPTestSucceeded
    $mpGroup += Test-NetConnection -Port 443 $MP3 -ErrorAction SilentlyContinue -WarningAction SilentlyContinue | Select-Object -Property ComputerName,RemoteAddress,RemotePort,TCPTestSucceeded
    $mpGroup | Format-Table

    Write-Host 'Testing connectivity to the software update points'
    $supGroup = @()
    $supGroup += Test-NetConnection -Port 80 $SUP1 -ErrorAction SilentlyContinue -WarningAction SilentlyContinue | Select-Object -Property ComputerName,RemoteAddress,RemotePort,TCPTestSucceeded
    $supGroup += Test-NetConnection -Port 8530 $SUP1 -ErrorAction SilentlyContinue -WarningAction SilentlyContinue | Select-Object -Property ComputerName,RemoteAddress,RemotePort,TCPTestSucceeded
    $supGroup += Test-NetConnection -Port 443 $SUP1 -ErrorAction SilentlyContinue -WarningAction SilentlyContinue | Select-Object -Property ComputerName,RemoteAddress,RemotePort,TCPTestSucceeded
    $supGroup += Test-NetConnection -Port 8531 $SUP1 -ErrorAction SilentlyContinue -WarningAction SilentlyContinue | Select-Object -Property ComputerName,RemoteAddress,RemotePort,TCPTestSucceeded
    $supGroup += Test-NetConnection -Port 80 $SUP2 -ErrorAction SilentlyContinue -WarningAction SilentlyContinue | Select-Object -Property ComputerName,RemoteAddress,RemotePort,TCPTestSucceeded
    $supGroup += Test-NetConnection -Port 8530 $SUP2 -ErrorAction SilentlyContinue -WarningAction SilentlyContinue | Select-Object -Property ComputerName,RemoteAddress,RemotePort,TCPTestSucceeded
    $supGroup += Test-NetConnection -Port 443 $SUP2 -ErrorAction SilentlyContinue -WarningAction SilentlyContinue | Select-Object -Property ComputerName,RemoteAddress,RemotePort,TCPTestSucceeded
    $supGroup += Test-NetConnection -Port 8531 $SUP2 -ErrorAction SilentlyContinue -WarningAction SilentlyContinue | Select-Object -Property ComputerName,RemoteAddress,RemotePort,TCPTestSucceeded
    $supGroup | Format-Table
}

如果你习惯手动先输入Enter-PSSession $Client进入远程会话后逐行跑命令，可以去掉外层的Invoke-Command包裹，进入会话后先手动赋值所有服务器变量，再按组收集结果通过Format-Table输出即可，效果完全一致。

内容的提问来源于stack exchange，提问作者Steve F