How to add more than one machine to the trusted hosts list using winrm

Question

To run powershell commands on a machine from a remote machine we have to add the remote machine to the trusted hosts list of the host machine.

I am adding machine A

Answer 1

I prefer to work with the PSDrive WSMan:\.

Get TrustedHosts

Get-Item WSMan:\localhost\Client\TrustedHosts

Set TrustedHosts

provide a single, comma-separated, string of computer names

Set-Item WSMan:\localhost\Client\TrustedHosts -Value 'machineA,machineB'

or (dangerous) a wild-card

Set-Item WSMan:\localhost\Client\TrustedHosts -Value '*'

to append to the list, the -Concatenate parameter can be used

Set-Item WSMan:\localhost\Client\TrustedHosts -Value 'machineC' -Concatenate

Answer 2

The suggested answer by Loïc MICHEL blindly writes a new value to the TrustedHosts entry.
I believe, a better way would be to first query TrustedHosts.
As Jeffery Hicks posted in 2010, first query the TrustedHosts entry:

PS C:\> $current=(get-item WSMan:\localhost\Client\TrustedHosts).value
PS C:\> $current+=",testdsk23,alpha123"
PS C:\> set-item WSMan:\localhost\Client\TrustedHosts –value $current

Answer 3

winrm set winrm/config/client '@{TrustedHosts="machineA,machineB"}'

Answer 4

I created a module to make dealing with trusted hosts slightly easier, psTrustedHosts. You can find the repo here on GitHub. It provides four functions that make working with trusted hosts easy: Add-TrustedHost, Clear-TrustedHost, Get-TrustedHost, and Remove-TrustedHost. You can install the module from PowerShell Gallery with the following command:

Install-Module psTrustedHosts -Force

In your example, if you wanted to append hosts 'machineC' and 'machineD' you would simply use the following command:

Add-TrustedHost 'machineC','machineD'

To be clear, this adds hosts 'machineC' and 'machineD' to any hosts that already exist, it does not overwrite existing hosts.

The Add-TrustedHost command supports pipeline processing as well (so does the Remove-TrustedHost command) so you could also do the following:

'machineC','machineD' | Add-TrustedHost