Problem with VNC

Posted on 2003-11-20
Medium Priority
Last Modified: 2010-03-19

I just got RealVNC for XP, and ran the VNC Server. And I tried connecting to my computer using VNC Viewer from another computer running XP, I tried putting in "myip:5800" and "hostname:5800", but both resulted in a "cannot connect" message. I tried it on several other computers with XP and it's the same problem. I even tried connecting it using my browser by typing in "http://ipaddress:5800"  but that didnt work either.

I disabled my firewall. (Strangely, my windows XP firewall option is "greyed-out" and I can't enable it).

What am I doing wrong? By the way, if I can't just put in the numerical ip address, how do I find my exact host name to put into the VNC viewer?

Question by:zxzwin
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LVL 35

Expert Comment

ID: 9795212
Where is "my computer" in relation to "another computer" - in other words, are they both on the same network?

If they aren't on the same network, then is there a definite route between them, somehow?  For instance, Computer 1 is on network A and computer 2 is on network B and Network A and Network B have a clear route established between them?

Believe it or not, yhr IP address (or the route to the IP address) is just as important as what IP port you hope to use to connect,

LVL 18

Expert Comment

ID: 9795213
Don't use the port number in the VNC dialgue box, numbers following the host in this box refer to instances of vnc on the server or 'display numbers', by default it's 0

if I can't just put in the numerical ip address, how do I find my exact host name to put into the VNC viewer?
If it's a public IP address with a DNS entry, do a reverse lookup (you need to know the IP!)
set querytype=PTR
LVL 35

Expert Comment

ID: 9795236
You may want to review the documentation -

For the server:


For the viewer:

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LVL 18

Expert Comment

ID: 9795242
just dawned on me, are you trying to use the Java vnc in a browser on port  5800?

The url would be


If you're using the VNC viewer, just use the IP address...

if neither of those work, you'll have to explain your setup a little more thoroughly.

LVL 10

Expert Comment

ID: 9801408
i dont know on what logic, but vnc also runs on port 5900 or 5901.
i check it this way,
go to the server and in the command prompt, do a "netstat -a",
and look for a 4 digit port number starting with 5,
that is mostly the port which is being used.
try to connect that.
LVL 10

Accepted Solution

kiranghag earned 1500 total points
ID: 9801413
and to add onto chicagoan's comment...

vnc allows you to connect using two methods,
1. using its own vnc viewer
2. using java compliant web browser

if u r using vnc viewer, u need to specify the "display" number on which the server is running, this can be optional too. i just provided server ip and it connected. and this display number is in lower numerical range, starting with 0, 1, ...

but when u use browser to connect, u ned to provide port number associated with each display.
display 0 may correspond to 5800, 1 may correspond to 5900...

make sure u dont jumble between the twos.
LVL 10

Expert Comment

ID: 9801417
sorry for this fragment, but forgot to add onto previous that i guess u can see the current display number from the system tray icon.
LVL 18

Expert Comment

ID: 9801421
default is 5900 for viewer display 0, 5901 for display 1, etc
5800 0 for http/java diplay 0, 5801 for 1 , etc

Expert Comment

ID: 9810804
Could be a typo. If you're logging in using the VNC viewer, using "machine:x" makes it think "x" is the machine number of the system you're trying to conenct to. It adds this number to 5800 or 5900 to get the port number. If you want to explicity state the port number you are connecting to, you need to use two colons -- "machine::portnum".

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