VNC User Guide - RealVNC

Chapter 2: Getting Connected
b. Examine the appropriate section of the Get Started section:
In this example, VNC Server is running on host computer 192.168.0.133 and listening on port 5901.
Allowing network communications through a firewall
If the host computer is protected by a firewall, then the firewall must be configured to allow incoming network
communications to the port on which VNC Server is listening. To find out which port this is, see Qualifying a
network address with a port number on page 30.
The firewall might be automatically configured by the operating system of the host computer. If not, you will
probably see the following error message when you connect from VNC Viewer:
Connection timed out (10060)
The instructions for adding exceptions for ports are specific to firewalls. If you do not have access to the host
computer, ask a host computer user to consult the manufacturer’s documentation.
Miscellaneous connection messages
This section explains various error messages you might see.
Failing to authenticate correctly
If you see the following error message:
Either the username was not recognized, or the password was incorrect.
then you have not authenticated correctly to VNC Server. Note that user names and passwords are casesensitive.
If you do not know the correct user name or password, and you do not have access to the host computer,
you will need to consult your system administrator or a host computer user. If you do have access to the host
computer, and sufficient privileges to configure VNC Server, you may be able to relax the authentication
rules. For more information, see Relaxing the authentication rules on page 104.
Failing to authenticate as ‘you’
If you see the following error message:
Access is denied.
then VNC Server has been configured to require the credentials of a host computer user. Your user name
and password, however, have not been added to the authentication list.
If this is the case and you do not have access to the host computer, you will need to consult your system
administrator or a host computer user. If you do have access to the host computer, and sufficient privileges
to configure VNC Server, you may be able to register your credentials. For more information, see Managing
users and groups in the authentication list on page 102.
VNC User Guide 31