CmdID / PowerShell / Cmdlets / Set
Set-PerimeterConfig
Use the Set-PerimeterConfig cmdlet to modify the list of gateway server IP addresses that have been added to the cloud-based safelists. Exchange PowerShell reference
From the Exchange PowerShell reference 4 parameters Its page in the reference
Parameters
-IdentityThis parameter is reserved for internal Microsoft use.-Confirm, -cfThe Confirm switch specifies whether to show or hide the confirmation prompt.-GatewayIPAddressesUse the GatewayIPAddresses parameter to create or modify a list of gateway server IP addresses to add to IP safelists.-WhatIf, -wiThe WhatIf switch shows what the command does without making any changes.