Enable RemMgmt (All Traffic) Firewall-Server Core.ps1

# One of the first commands to issue on a new Windows Server Core 2012 system
New-NetFirewallRule -DisplayName "1111 WARNING - Allow All Traffic" -Action allow

#Run this on server connecting to remote CORE server:
winrm set winrm/config/client @{TrustedHosts="*"}

#Run this on both server and client system:
winrm quickconfig -q

# now you can connect to remote system with Server Manager and add/remove roles and features