Add xrdp port on firewalld (CentOs)

1. Check xrdp process

sudo ps aux | grep xrdp

2. Check xrdp service (default port 3389)

sudo netstat -ntlp | grep -i xrdp

3. Edit /usr/lib/firewalld/services/xrdp.xml for Remote Desktop (add port 3389)

    PS: xrdp.xml will add a "xrdp" item on firewalld GUI

<?xml version="1.0" encoding="utf-8"?>
<service>
  <short>xrdp</short>
  <description>This option allows you to access Remote Desktop.</description>
  <port protocol="udp" port="3389"/>
  <port protocol="tcp" port="3389"/>
</service>

4. Start xrdp

sudo systemctl start xrdp.service
sudo systemctl status xrdp.service

5. Add xrdp service for firewalld and reload firewalld

sudo firewall-cmd --permanent --add-service=xrdp
sudo firewall-cmd --reload
sudo systemctl status firewalld

6. Config SELinux

sudo chcon --type=bin_t /usr/sbin/xrdp
sudo chcon --type=bin_t /usr/sbin/xrdp-sesman

7. Check xrdp service (default port 3389) again

sudo netstat -ntlp | grep -i xrdp

Refer to:
  1. http://www.itzgeek.com/how-tos/linux/centos-how-tos/install-xrdp-on-centos-7-rhel-7.html