Cannot Access remote CentOS machine using VNC

Question

I am trying to connect to a remote CentOs machine through VNC to get a graphical display.

I have followed the steps mentioned in https://www.howtoforge.com/vnc-server-installation-centos-6.5 to install and configure VNC server on my CentOS machine.

I have used the Iptable command to open 5901 port as well.

However on my ubuntu machine when I type vncviewer and type my the remote server's IP address I get the following error:

main:        unable to connect to host: No route to host (113)

Answer 1

It worked by specifying the port number along with the IP Address:

vncviewer IPAddress:5901