ERROR: Failed to connect to server!

catplus · Post by **catplus** » 2005-12-27 02:46

Hello all!

My host's operating system is Windows 2003 server and am using SonicWall TZ170 as a router and firewall

At SonicWall, I created a TCP 5900 service and an access rule forwarding traffic from WAN * to my private IP 198.168.0.10

From an external computer, I installed UltraVNC and launched VNCViewer with following info:

VNC Server [1] 69.22.199.163 and [2] 69.22.199.163:5900 and [3] 69.22.199.163::5900 and each trial returned the error:

FAILED TO CONNECT TO SERVER!

The Port in all three instances returned 5900 whether the VNC Server specified <none/blank>, :5900 or ::5900

The line Encoder returned blank
The line Speed read:123 KBIT/s
The line Bytes sent/recived returned 0

Where am I going wrong?

Thanks and with season's greetings
Mickey

bevtech · Post by **bevtech** » 2005-12-27 16:15

Well mikey,

I have not have success getting the Ultra VNC to run through a Sonic Wall tz170 so far except for using VPN. I have set rules etc with no success. I do think the sonic walls deep packet inspection and stateful packet doesnt allow two way traffic. I have tried this on at least 3-4 sonic walls and the only way I can get it to work is to run it through a vpn.

I think that another random port is needed that is established when you connect to the server. I have seen that port established by using tcpview and most firewalls seem not to block external traffic but sonicwalls will..

Just a theory on way Ultra VNC doesnt work through Sonic walls.

So if you want to use Ultra VNC then try running it through a Sonic Wall VPN client and see how that works for you..

Take Care,

yleclerc · Post by **yleclerc** » 2005-12-27 17:26

I do not get the difference with the connecting problem between UltraVNC and RealVNC. I was always able to set up a rule on Sonicwall units for RealVNC servers over the standard IP port 5900. What is the difference with UltraVNC?

catplus · Post by **catplus** » 2005-12-27 17:50

Bevtech and Yleclerc,

RealVNC and UltraVNC are almost identical... I believe the only difference is that with UltraVNC you get the control of client's system without them having to install any software

Coming back to my problem, I do not have the option of transacting through a VPN tunnel... since that is only possible if the client has similar hardware/software available. And I can easily configure and forward ports with SonicWall which does what you tell it to do.

Are there TCP ports besides 5500 and 5900 that need to be opened and forwarded?

I am hoping to establish a connection with the help of you guys!

Thanks
Mickey

yleclerc · Post by **yleclerc** » 2005-12-27 18:17

catplus wrote: ...
RealVNC and UltraVNC are almost identical... I believe the only difference is that with UltraVNC you get the control of client's system without them having to install any software
...

This is not true! You still need to have a "server" installed so that the "viewer" can connect to. VNC does not appear to "connect" without some type of "host" to receive the requests. This usually "WinVNC" or maybe SC VNC (which I never used??)

catplus · Post by **catplus** » 2005-12-27 18:38

Yleclerc

Ofcourse, the server has to be running... on the host side!

On my server, with TCP Ports 5500 and 5900 forwarding to the private IP of my machine, I am running both, the VNCviewer -listen (green icon) and WinVNC (blue icon)

Client is e-mailed a remote.exe compiled with my settings. When they save the file on their desktop and try to launch the client.exe, they get two alternating error messages: [1] FAILED TO CONNECT TO SERVER or [2] UNSPECIFIED ERROR

Hoping that explains my question

Mickey

yleclerc · Post by **yleclerc** » 2005-12-27 19:03

have you tried to also open up 5800? This is normally used for the Java VNC client access over HTTP.

Also, have you contacted your Internet Service Provider so as to see if they have imposed limits to the higher end IP ports? Some ISPes now limit the IP ports above 1024 in hopes of limiting viruses/trojans/worms and "illegal" P2P sharing.

catplus · Post by **catplus** » 2005-12-27 20:35

Hello again Yleclerc

I opened that port too... no connection!

bevtech · Post by **bevtech** » 2005-12-27 21:11

catplus,

Well if you happen to figure it out let me know.. If I happen to figure it out I will let you know. But I have spent serveral hours fighting with sonicwall TZ 170 , Sonicwall soho TZw with no success. Real VNC may work but I as far as know Ultra VNC 1.0.1 will not work by opening the normal ports ( or ports or your choosing)like the documentation suggusts..

Can you create a VPN tunnel and use it that way???

catplus · Post by **catplus** » 2005-12-27 21:15

Bevtech

Even if I could open a tunnel, the option would be unworkable since the clients I support may not have a device with which I must communicate in a VPN tunnel instance

Lets hope we find an answer.... from the moderators of the forum perhaps!

Thanks anyways
Mickey

yleclerc · Post by **yleclerc** » 2005-12-27 21:21

catplus

Is this Sonicwall using static IP addresses? I have encountered a Sonicwall unit where I could not access a "port-forward" scheme on the assigned IP address of the Sonicwall. In trying other tests, I was able to connect to the "port-forwarded" access from another IP address as part of "assigned" IP address range.

IE:

xxx.yyy.zzz.114 is the IP address of the Sonicwall. All rules are based from this address.

xxx.yyy.xxx.116 is the forwarded port access IP address.

BTW: I did not see any "port-forwarding" set up for the 116 address.

yleclerc · Post by **yleclerc** » 2005-12-27 21:31

A further post to my preivous one!

I went back to the Sonicwall TZ170 unit that I mentioned that I was not able to route the port-forward through the main IP address. I discovered more details.

Sonicwall has a feature known as ONE-TO-ONE NAT, which allows you to route an internal private IP address to a public IP address. If this feature is activated, you need to route through using the assigned IP address.

catplus · Post by **catplus** » 2005-12-27 21:43

Yleclerc,

Yes... one-to-one natting works when you have a T1 connection with a suite of IP addresses given out to you. Most of us have a DSL or cable connectivity with a singular dynamic IP, so in SonicWall Firewall, you first define a service and then create an access rule

Regards
Mickey

bevtech · Post by **bevtech** » 2005-12-27 22:08

Well I will check into to see what options I have. I mostly have Nat enabled on my Wan connections. I have defined the serivices and then created the rules.

Glad Your is working catplus and I thank Yleclerc for the tips I will do some checking and see if I can get mine to work as well..

Cheers,

catplus · Post by **catplus** » 2005-12-27 22:12

Bevtech,

No... I cannot connect... all I am saying is that all port forwarding, etc. etc. is good! Except that I cannot connect!

Good luck!