You can enable
and disable access to the VNC server by restricting IP subnets in
addition to the existing server password protection. This
prevents people that are not on your network from attempting brute
force attacks on your VNC servers. This feature works best
when you standardize on UltraVNC.
We will start by adding an entry
that will block every IP address from accessing our servers.
We will follow with another entry that will allow only our own
subnet to access the network and then another that will allow a
different subnet access but will alert the user of the computers
before and allow them to reject the connection.
How It's Done
Start by creating a new deployment profile. One way to
do this is to click on the
toolbar button.
Create a new deployment profile or edit an existing one that
is based upon the 'Ultra' flavor of VNC.
You come to a screen with the 'Authorized Hosts' option that
you see below.
Deny All: Click the Add button to add a subnet.
You will see the window below open up:
Click on the Deny button and leave the text box blank.
This tells the server to deny any connection to it from any
address. The next couple of steps will partially override
this setting to allow certain subnets access.
Click the OK button
Allow Some: Follow step 3 again to set another host
mask and this time, click Allow and put in the first part of
your subnet that you want to allow access to the servers.
For example, if your network is numbered 192.168.0.1 through
102.168.0.255 and you want to allow all of them, then just enter
192.168.0 and hit OK.
Question Some: Now, we want to add a subnet of
helpdesk people so that they can also remote control computers
but we want the end users to know if they are attempting to do
so. We will create a rule that will query if a connection
request comes from their subnet of 192.168.1.X:
Now, our screen looks like this and our objectives have been
completed: