Accessing CentOS 7 via RDP 

Install needed packages:

$ yum install epel-release

$ yum install xrdp tigervnc-server tigervnc-server-module

Change SELinux context for xrdp:

$ chcon -t bin_t /usr/sbin/xrdp

$ chcon -t bin_t /usr/sbin/xrdp-sesman

Open rdp port in firewall:

$ firewall-cmd --zone=public --add-port=3389/tcp --permanent

$ firewall-cmd --zone=public --add-port=3389/udp --permanent

$ firewall-cmd --reload

Enable and start xrdp service:

$ systemctl enable xrdp

$ systemctl start xrdp

Modify GNOME Display Manager custom:

$ vi /etc/gdm/custom.conf

[security]

AllowRemoteRoot=true

DisallowTCP=false

[xdmcp]

Enable=true