PureBasic Forums - English

This is mainly addressed to Freak, but anyone else with a clue can chip in.

I've got the VNC server running on my home PC, but when I tried to "log in"
from my work PC I got this error message in a little Java window:
At home, my PC normally runs ZoneAlarm but I had it turned off for this test.
Also, the Windows XP firewall is NOT enabled either... so I don't know why I
can't connect. Can my employer's PC be forcing an outbound restriction?
I would doubt it, as I can browse any other web sites without problems.
I do have a password set up with VNC but I never get that far to actually
enter it... I only get to choose a server (my home PC's IP address) and
then the error above happens.

(@TerryHough: I got your PM about VNC but your info is more confusing than
Freak's... I'll try to get Freak's method working first before I embark on any
more elaborate uses of remote control).

EDIT: Actually, I just saw this web page regarding the error:
http://www.realvnc.com/pipermail/vnc-li ... 27831.html
What does "redirecting port 5900" mean? Does it mean the server's
"accept connections on port #" and "serve java viewer on port #" should
be the same port number? The former is set to 5900 and the latter to
5800, which are the defaults... I guess I'll have to wait until tomorrow
to try again (grrr!).

Is your home machine connected directly to the internet or through a gateway? In my case I have an ADSL modem connected to the internet and several boxes connected to the modem via internal lan. To get requests *from* the internet to a specific machine I need to tell the gateway to forward specific TCP and UDP ports. This is what "redirection" is.

> Is your home machine connected directly to the internet or through a gateway?

I wouldn't have a clue. How do I find out? According to Device Manager,
my modem is a D-Link DSL-200 USB ADSL Modem(WAN). I connect to my
ISP via PPPoE (or whatever it is) -- I think. Pretty sure I've seen that text
a lot during my setup of it. The "number" I connect to (for my ISP) is just
"8,32" along with my username and password.

Just had a quick glance at dlinks website. I'm assuming it does not do any packet filtering at all so I don't think this is your problem. If your VNC server is the machine in your sig then I would look at XP's settings.

Edit: From info in your first post I now guess it's your employers network (routers/firewall) that's the problem.

> This is mainly addressed to Freak, but anyone else with a clue can chip in.

Sorry, i'm not really an expert on this either.

I usually use this only in local networks to access my server, so i don't
really know what might be wrong there.

btw: on the new VNC the CLIENT needs to accept the connection [a msnbox where you can choose yes or no], and if nothing gets touched the connection will automatically be refused...

this can of course be turned off, but default its on!

@PB

Sorry, didn't mean to be confusing...

VNC is really two pieces of software:
1) VNC Server - this is the server piece you are running on your machine to accept and handle connections, pass on commands, etc.
A case sensitive password must be established in its configuration before it will accept connections.
2) VNC Viewer - this is the client end piece. Run this at the client machine and it will ask for the URL/IPAddress of the server. It will then contact the server and when connected the server will ask for the password. Enter the case sensitive password for authentication and the serve will grant access. The Viewer then communicates with the server to provide display, mouse, and keyboard control of the server machine.

Hint: Right click on the top window desctiption bar to see the viewer's menu of actions.

If possible, attempt to use the Viewer to access your server before you attempt to contact it using a browser. I have seen a couple of server systems that wouldn't work that way, even though the option was checked. I suspect the Java software on that machine wan't up to date.

Freak's suggestion of using a browser to access the Java applet portion of the server also works well. The server's Java applet option box must be checked. It only advantage though, is that it does not require any client software, you can just use the standard browser. There are fewer features available and the display size is a bit more restricted.

I am not an expert, but I am very experieced using VNC. Probably utilize it 20 times a day to control various systems

Good luck
Terry

Edited later: I am refering to the download available from RealVNC which I use. I have found it very stable. About a year ago, I gave TightVNC a spin, but found it locked up regularly and dropped it. However, it has been updated since then and may be acceptable now.

PB

Has this worked before?

If not, are you sure you have the right address for your home machine?

Presumably the latter is through your Internet Service Provider (ISP) and is thus likely to change - often if on dial-up, less often if on Broadband unless of course you subscribe to a fixed address system.

The way I arrange it is that I ask people to go to a 'secret' page on my web-site. The page has got a counter active.

Thus all I have to do is look out for a hit on that page which will give me the current address of the source.

I use VNC now in a way similar to what you want PB, this is what i did to get mine up and running:
This worked fine for me when i checked my desktop from work going through our systems firewalls etc.. I also disabled the MS firewall at home too.

PB wrote:What does "redirecting port 5900" mean? Does it mean the server's
"accept connections on port #" and "serve java viewer on port #" should
be the same port number? The former is set to 5900 and the latter to
5800, which are the defaults... I guess I'll have to wait until tomorrow
to try again (grrr!).

The port numbers should be different. The "accept connections" one is the port to use when connecting with the VNC client software. The "serve java" is the port to use from your web browser / java.

Personally I prefer the client software as there is an option in the system menu for sending a ctrl-alt-del key combination which doesn't seem to be there in the java one (and pressing those keys operates on my Win32 box at work). I don't think ctrl-alt-end works, which is what the MS RDP client / server uses.

Your employer could be blocking non-standard ports, such as 5800 and 5900. Your web browsing would be on 80 so that's completely different from your VNC.

Hi all, I just got to work and still can't connect -- ARGH! Now I have to
wait 9 hours before I can get home and change things.

@eevee: Yes, I definitely have the right IP address for my home PC. It's
ADSL with a dynamic IP, and I've been connected with the same IP for a
few days now. I always double-check it before I leave for work anyway,
just in case.

@Kale: Thanks for your detailed description for ZoneAlarm -- I'll have to
do this when I get home, in case ZA is the cause... but I did try it with ZA
not running, so I doubt that's the problem.

@tinman: Maybe you're right about my work PC not being allowed to
connect to non-standard ports... maybe if I set VNC Server to port 80
then it'll work? I'll have to try.

@thefool: When you say "client" you mean my PC at work, yes? If so,
I've not seen an option with VNC Viewer (v4) like that...? And this also
answers another query: I've tested the VNC Viewer (in addition to the
web Java applet) and it also doesn't connect either -- I get this error:
"Unable to connect to host: Connection refused (10061)".

Frustrating!

Well if you want to try to test your outgoing VNC connection I can let you have access to my computer to try it.

As long you promise not to break anything >)

PM me for the info.

@tinman: Maybe you're right about my work PC not being allowed to
connect to non-standard ports... maybe if I set VNC Server to port 80
then it'll work? I'll have to try.

Not sure what version of VNC you are using, but with TightVNC, you can only use 58xx for the web based client, and 59xx for the thick client (where xx is the display number, defaults to 00).

[1st edit] I wonder if one could NAT the external port 80 to an internal port 5800?? Hmmm....

[2nd edit] DOn't get your hopes up, looks like the web client still uses port 5900 to make a connection...

[3rd edit] I cound not find a way around the use of port 5900. Port 80 NAT's fine to 5800 but then the client tries to use port 5900 for the session. I found this site while looking for options: http://www.logmein.com
It says it is free (but offers a pro version that costs). I loaded it and will test it tomorrow on our corporate WAN. Looks like it uses Java also.

Some info regarding the "10061" error message that I got with VNC Viewer:
I went to these forums later that day and got this error from Internet Explorer.
Maybe it can somehow explain why VNC Viewer can't connect to my home PC?

@Tinman: Maybe this weekend I can try connecting to your PC from my one?
That would be interesting as it would show if my work PC is the problem.

PB wrote:@Tinman: Maybe this weekend I can try connecting to your PC from my one? That would be interesting as it would show if my work PC is the problem.

Yeah, if I'm around. Don't think I've got any plans to be away from home.