White Papers

35 Accessing Remote Desktop using VNC on Dell PowerEdge Servers and MX7000 Modular Infrastructure
8 Troubleshooting issues when accessing remote desktop
using VNC
The following procedures assist in troubleshooting the VNC connectivity.
Symptom
Possible Causes
Resolution
Unable to connect
to the iDRAC from
VNC client
Settings are incorrect
Ensure that the VNC server is enabled. Verify and/or
adjust the remote host IP, port number, encryption
settings, and password so the client and server
values match. If using VNC over SSH, do not enable
TLS encryption. If tunneling, set the VNC client to
use the ports required for tunneling.
Network is unreachable
Ensure that:
Network cables are attached
Wi-Fi connection is available
Required VPN connections are started
Network and firewall settings allow the iDRAC to be
reached from the client. It may be useful to attempt to
connect to the iDRAC GUI from the client device.
VNC client does not
support iDRAC
encryption
Switch to a VNC client that supports secure
tunneling, or use an external secure tunneling
program such as ‘ssltunnel’. It may be useful to
attempt to connect to the iDRAC with ‘encryption’
disabled.
Lost VNC
connection to VNC
server
VNC session timeout
VNC session remains active until session timeout
period is configured in the iDRAC VNC server
settings. Allowed session timeout period range is 60–
10800 seconds.
Host system power
cycled and with iDRAC
NIC in shared mode.
When iDRAC NIC is in shared mode and the host
system is power cycled, the network connection is
lost for few seconds. During this time, if you perform
any action in the active VNC client, the VNC session
may close. You must wait for timeout (value
configured for the VNC Server settings in the
Services page in iDRAC Web interface), and then
restart the VNC connection.
VNC Client window
minimized for more than
60 seconds
If the VNC client window is minimized for more than
60 seconds, the client window closes. You must start
a new VNC session. If you maximize the VNC client
window within 60 seconds, you can continue using it.
VNC server displays
active sessions,
when no clients are
actually connected.
Unable to connect
to iDRAC from VNC
client.
VNC server state is
invalid
Reset the iDRAC. Alternatively, disable and reenable
the VNC server by using the iDRAC GUI. Consider
reducing the VNC Server timeout value. Ensure the
latest firmware is installed.
VNC client indicates
that the video is
corrupted
VNC client is not
compatible
Use a known compatible client such as those listed in
this technical white paper.