Today’s cmdlet of the day is PowerShell Test-Connection. Test-Connection is a cmdlet that not surprisingly tests your network connection. Think of Test-Connection as PowerShell’s implementation of the popular ping utility. Even though both have ICMP in common, you’ll see that the two methods are a little different under the covers.
Using this cmdlet is simple. At its most basic, just specify a ComputerName parameter, and it will send four ICMP requests to the destination host.
PS> Test-Connection -ComputerName google.com
Source Destination IPV4Address IPV6Address Bytes Time(ms)
------ ----------- ----------- ----------- ----- --------
MACWINVM google.com 172.217.0.14 2607:f8b0:4009:80c::200e 32 47
MACWINVM google.com 172.217.0.14 2607:f8b0:4009:80c::200e 32 90
MACWINVM google.com 172.217.0.14 2607:f8b0:4009:80c::200e 32 88
MACWINVM google.com 172.217.0.14 2607:f8b0:4009:80c::200e 32 205This output looks similar to ping.exe and, on the surface, it is but Powershell test-connection issues the ICMP request a little differently. Unlike ping.exe, Test-Connection is using the local computer’s WMI class Win32_PingStatus to send the ICMP request. Using the local WMI repository means you’d better be sure your local WMI repository is healthy else Test-Connection will not work.
PowerShell Test-Connection’s Object Output
Also, as with the beauty of PowerShell, this cmdlet doesn’t merely return what immediately shows up in the console. We see rich objects that we can gather more information from.
If I assign the output to a variable and then check out the properties, you can see that I’ve gathered a lot more useful information.
PS> $pingResults | Get-Member
TypeName: System.Management.ManagementObject#root\cimv2\Win32_PingStatus
Name MemberType Definition
---- ---------- ----------
PSComputerName AliasProperty PSComputerName = __SERVER
Address Property string Address {get;set;}
BufferSize Property uint32 BufferSize {get;set;}
NoFragmentation Property bool NoFragmentation {get;set;}
PrimaryAddressResolutionStatus Property uint32
PrimaryAddressResolutionStatus {get;set;}
ProtocolAddress Property string ProtocolAddress {get;set;}
ProtocolAddressResolved Property string
ProtocolAddressResolved {get;set;}
RecordRoute Property uint32 RecordRoute {get;set;}
ReplyInconsistency Property bool ReplyInconsistency {get;set;}
ReplySize Property uint32 ReplySize {get;set;}
ResolveAddressNames Property bool ResolveAddressNames {get;set;}
ResponseTime Property uint32 ResponseTime {get;set;}
ResponseTimeToLive Property uint32 ResponseTimeToLive {get;set;}
RouteRecord Property string[] RouteRecord {get;set;}
RouteRecordResolved Property string[] RouteRecordResolved {get;set;}
SourceRoute Property string SourceRoute {get;set;}
SourceRouteType Property uint32 SourceRouteType {get;set;}
StatusCode Property uint32 StatusCode {get;set;}
Timeout Property uint32 Timeout {get;set;}
TimeStampRecord Property uint32[] TimeStampRecord {get;set;}
TimeStampRecordAddress Property string[] TimeStampRecordAddress {get;set;} TimeStampRecordAddressResolved Property string[]
TimeStampRecordAddressResolved {get;set;}
TimestampRoute Property uint32 TimestampRoute {get;set;}
<SNIP>If you’re testing internal hosts, Test-Connection will use DCOM to authenticate to remote hosts. By default, it will use Packet level DCOM authentication but the authentication type can always be changed with the DcomAuthentication parameter.
Using Background Jobs
This cmdlet can also run as a background job. Background jobs come in handy if you’ve got lots of remote computers to ping and rather than wait forever for ones that’ll eventually time out, just send it to a background job.
According to the PowerShell help for Powershell test-connections, it says that PowerShell remoting must be enabled on both the local and remote computers, but this is not true. As you can see below, I’m testing google.com, and the command still works great.
Keeping it Simple
Finally, if you’re just looking for a binary yes/no answer to if a computer is responding or not, you can always use the Quiet parameter. A common string I always use to quickly see if a server is online or not is to use Quiet and Count of 1 to force Test-Connection to send a single ICMP request.
PS> Test-Connection -ComputerName google.com -Quiet -Count 1
TrueThat’s it for our cmdlet of the day! We covered the majority of what’s possible with Powershell test-connection but, as always, check out the PowerShell help content or head over to the Microsoft documentation for a full breakdown.
