Virtual Network Computing Troubleshooting

[ehanes7612]

anyone know about virtual network computing? I am trying to use a VNC with my mac via a server connected to my terminal

and I keep getting this in the VNC window when I try to connect with the log number I get from the terminal

my input

"vncviewer -via [email protected] localhost:21"

vnc response:

"unable to resolve host vncviewer -via [email protected] localhost:unknown error"

asking other places also, thought I would try here

 

[ksriramkumar]

Not sure if it would help.

do a ping of bowser.phys.wvu.edu and localhost and check if the host is getting resolved before you attempt a VNC.

secondly usually the last part of localhost:21 is to denote a display terminal number and is usually a :0 or :1 (depends on setup)

 

[Rob Zuiderwijk]

I'm not quite sure what you're trying to do.

localhost is a kind of alias that refers to your own machine. It's a loopback address.
The ':21' you added to the localhost address indicates that you want to connect to your localhost over port 21, which is usually the default port number for basic FTP network traffic.

I'm unfamiliar with Apple equipment but I wonder if port 21 is the port you want to use to setup your console/terminal session.

Rob.

 

[naoki]

On Mac OS-X, I'm using the VNC client (Screen Sharing) which is installed by default. I like the scaling of Screen Sharing better than some others I have tried (TurboVNC and TigerVNC, I think).

I haven't done VNC through ssh-tunnel. Are you using TigerVNC?http://tigervnc.org/doc/vncviewer.html

Can you resolve the name (localhost) with

nslookup localhost

or ping suggested by ksiramkumar? It should say 127.0.0.1. If not, you might want to check if /etc/hosts has localhost listed. I'm guessing the command line vncviewer is probably using /etc/hosts, but with Mac, there is another non-unix way of looking up the domain names.

Does it work if you manually establish the tunnel (instead of -via) like this?
http://www.cl.cam.ac.uk/research/dtg/attarchive/vnc/sshvnc.html

 

[ehanes7612]

I'm not quite sure what you're trying to do.

localhost is a kind of alias that refers to your own machine. It's a loopback address.
The ':21' you added to the localhost address indicates that you want to connect to your localhost over port 21, which is usually the default port number for basic FTP network traffic.

I'm unfamiliar with Apple equipment but I wonder if port 21 is the port you want to use to setup your console/terminal session.

Rob.

21 is the number i get when I run "vncviewer" on my terminal after I ssh into the remote server..I am supposed to use it in the above line of code in the vnc window on my mac

 

[ehanes7612]

I will try some of the advice I got here. I have a tech guy helping me on this at the server but it's difficult to communicate as he is really busy

 

[ehanes7612]

On Mac OS-X, I'm using the VNC client (Screen Sharing) which is installed by default. I like the scaling of Screen Sharing better than some others I have tried (TurboVNC and TigerVNC, I think).

I haven't done VNC through ssh-tunnel. Are you using TigerVNC?http://tigervnc.org/doc/vncviewer.html

Can you resolve the name (localhost) with

nslookup localhost

or ping suggested by ksiramkumar? It should say 127.0.0.1. If not, you might want to check if /etc/hosts has localhost listed. I'm guessing the command line vncviewer is probably using /etc/hosts, but with Mac, there is another non-unix way of looking up the domain names.



Does it work if you manually establish the tunnel (instead of -via) like this?
http://www.cl.cam.ac.uk/research/dtg/attarchive/vnc/sshvnc.html

Using Turbo VNC..it's what my server people told me to use

pardon my ignorance, because all of this is new to me..what exactly do you do when you 'ping' ?

when I run "nslookup localhost" I get 127.0.0.1

 

[naoki]

Ping sends a packet to see if you can reach to the host. But it seems localhost is resolving ok.

Looking at this (Section 6):
https://cdn.rawgit.com/TurboVNC/turbovnc/2.1.1/doc/index.html
Did you try

vncviewer -tunnel [email protected]

? If it doesn't work, does the following work?

ssh -L 5921:localhost:5921 [email protected]

Did you check if firewall is blocking the access? You can disable it temporarily in System Preferences->Security&Privacy->Firewall tab to see if it makes a difference.

Is port 5921 used by another program? You can try

lsof -i:5921

If it's not used, it shouldn't return anything.

 

[ehanes7612]

Ping sends a packet to see if you can reach to the host. But it seems localhost is resolving ok.

Looking at this (Section 6):
https://cdn.rawgit.com/TurboVNC/turbovnc/2.1.1/doc/index.html
Did you try

vncviewer -tunnel [email protected]

? If it doesn't work, does the following work?

ssh -L 5921:localhost:5921 [email protected]

Did you check if firewall is blocking the access? You can disable it temporarily in System Preferences->Security&Privacy->Firewall tab to see if it makes a difference.

Is port 5921 used by another program? You can try

lsof -i:5921

If it's not used, it shouldn't return anything.

Thanks , will try this

 

[ehanes7612]

got it to work..IT guy from the school's server walked me through it..took awhile though