Instructions for accessing a UNIX host at Simonson Technology Services using SSH and VNC
If you are participating in a class where you will connect to Simonson Technology Service’s equipment from a remote location, you may need one or more of the following utilities to get the most out of your learning experience. Your instructor will be able to provide specific guidance on what utilities are required for the class, and will also provide the address and name of the machine you will be connecting to.
Interactive connectivity to the machines at STS can be gained using SSH. A graphical user interface, or GUI, can be gained using VNC and SSH together. Depending on the requirements for the class, you may need to have access to a graphical interface to run GUI programs. Examples of graphical programs are the Veritas Volume manager GUI, or the Solaris Management Console.
SSH – (or Secure SHell) is a program for connecting to, and executing commands on a remote machine. It provides secure, encrypted data transfer over an insecure public connection. It has other benefits that are useful in a network environment, such as allowing port forwarding, data compression, and secure ftp. SSH by itself bears a strong resemblance to rsh, rlogin, and is similar to telnet.
VNC – (or Virtual Network Computing) allows a user to receive a Graphical User Interface from a remote host. It is available for most major operating systems and is generally easy to configure.
Requirements:
To connect to a host at STS, you will need the ability to run programs, view the output, and have interactive access on a computer with Internet connectivity. In most cases, you will be required to download programs, decompress these programs if they are compressed, and add software to this computer. In addition, you will most likely need to have some familiarity with executing programs via the command-line.
Step 1 – Check Connectivity:
This step simply establishes basic connectivity to the STS host. This connectivity is required before subsequent steps can be taken to access the machine, and participate in the class from the remote location.
Before class starts, attempt to ping the machine you have been assigned. Execute the following from the command line (or command prompt / MS-DOS prompt as appropriate) on your machine, or if you prefer, use a third-party utility. Replace the xxx below with the appropriate number provided by your instructor. At the end of this document there is a list of IP addresses for classroom machines at STS.
# ping 207.228.42.xxx
Depending on your operating system, the output from the command will indicate that the machine at that address is “alive”, or will show statistics for the efficiency of the connection to the target address. Other responses like “unreachable”, “no response”, or “request timed out,” indicate some sort of networking problem. Try going to http://network-tools.com and enter the IP address of the machine you’re trying to reach and click “Submit”. The TraceRoute messages will indicate the efficiency of the connection between network-tools.com in Toronto, Ontario and our machines in Reno, Nevada. A “Trace complete” message indicates a working connection. A failed trace attempt indicates a problem.
If you’re unable to ping the machine you’ve been assigned and network-tool’s utilities can’t reach it either, the problem is probably with STS. It’s possible that the machine is having the operating system installed on it, there is a network problem with STS’s ISP, or the machine has been temporarily disconnected for some other reason. Please call us and let us know, and we will be happy to determine the problem and find a solution. See the bottom of this file for contact information.
On the other hand, if ping doesn’t work from your local machine, but network-tools is able to trace a route to the host at STS, the connectivity problem is probably at your location. Please follow the standard troubleshooting procedures as specified by your facility, or Internet Service Provider. This may include contacting support staff. If following these procedures does not provide you with a solution, STS staff will be happy to provide additional information, and or basic troubleshooting.
Step 2 – Download the connectivity software
The next step will be to download and install any required software that is not currently installed on your machine. Generally and with some basic experience, installing these utilities is not difficult. But, if you are not certain that you can do this safely, please contact your system administrator, or a friend for guidance. Before installing anything, it’s a good idea to determine if that utility is already present. If you don’t know how to check for these utilities, again contact someone for assistance.
Installation techniques vary from operating system to operating system, but both SSH and VNC are commonly implemented in a wide range of different platforms and are available as free downloads.
NOTE: SSH is a standard component in Solaris 9, and most modern versions of Linux.
The version of VNC that is installed on the STS hosts is available at http://www.realvnc.com for a variety of different platforms. If you wish to see the history of VNC check out: http://www.uk.research.att.com/vnc/. There is also another open source version of VNC at http://www.tightvnc.com. All the versions of the viewers are compatible with the currently installed vncserver versions. At the realvnc.com site, simply click on the download button, fill out the optional information if you choose, select your operating system specific binaries, and proceed to download. The Solaris VNC packages are also available at http://sunfreeware.com.
The most common SSH utility for Windows is named PuTTY. You can download it from http://www.chiark.greenend.org.uk/~sgtatham/putty/ . *See Miscellaneous Section information on the putty suite of tools. If you are using Solaris, and SSH is not installed, you can download the Solaris openssh packages from www.sunfreeware.com. You are also required to download and install the openssl and zlib packages. The openssh source code, clients for other Operating Systems, including Linux, and thorough documentation is available at http://www.openssh.com.
Step 3 – Installation
For Windows:
PuTTY requires no installation. The download is an executable file. Make sure to save the putty.exe file(s) to a location you will remember. A suggestion might be the desktop. *See the Miscellaneous Section for more details.
VNC is downloaded as a .zip file. To install it do the following:
Extract the file to a temporary location, and double click on the executable installation program. A pop-up menu will appear, and ask you if you wish to install VNC. Click Yes
Click Next at the initial installation screen. Click Yes to agree to the GNU General Public License. Click Next to Agree to the default installation directory, which is C:\Program Files\RealVNC. (Or, you can change this if you wish)
Click Next for the full installation, or you can change this if you wish. Click Next to agree to the RealVNC Start Menu folder. Click whichever check boxes you wish to. I chose to agree to the Desktop Icon.
Review your options in the last screen, and click Install. Click Next after you read the license and warranty statement. Then click Finish to exit Setup.
To uninstall VNC, follow normal procedures for uninstalling an application.
For Solaris:
Installing OpenSSH can be done in several ways. The discussion of which is lengthy, but straightforward. Compiling the source code is beyond the scope of this document, and will not be discussed; neither will anonymous ftp, with which the familiarity of may be a requirement to download the Solaris packages.
At the time of this writing, OpenSSH 3.5p1, OpenSSL 0.9.6g, and zlib 1.1.4 are the most current versions. *There are security holes in some previous versions, and STS HIGHLY recommends that you upgrade to the latest versions.
You will need to install OpenSSH, OpenSSL, and Zlib at a minimum. You may also need to install prngd, which is an entropy gathering dameon, and optionally tcp_wrappers. The OpenSSH, and support packages at http://www.sunfreeware.com are supported by STS. There are excellent, detailed instructions for installing these packages on;
Solaris 2.5(.1), 2.6, and 2.7 at: http://www.sunfreeware.com/openssh26-7.html
Solaris 2.8 at: http://www.sunfreeware.com/openssh8.html
Solaris 2.9 at: http://www.sunfreeware.com/openssh9.html
These sites also have links to the SUN Blueprint PDF documents for installing this software as well. *Often times downloading from ftp://ftp.sunfreeware.com, as is directed in some of the documentation is difficult because of the large volume of traffic. There are several mirror sites that are listed at http://www.sunfreeware.com/ftp.html.
Installing VNC is simple. VNC can be downloaded from http://www.realvnc.com/download.html
Unzip the gzipped file vnc-3.3.6-sparc_solaris_2.5.tar.gz by typing:
#gunzip –c vnc-3.3.6-sparc_solaris_2.5.tar.gz | tar xBpf –
Change directory to the vnc installation directory.
Take a look at the README file if you wish. Alternately if you wish to just install the VNC package in /usr/local/bin, type:
#./vncinstall /usr/local/bin
If you wish to install the Java client, the make a directory for it, and copy the java classes directory to it.
# mkdir –p /usr/local/vnc/classes
#cp classes/* /usr/local/vnc/classes
There are additional instructions on doing the light configuration that must take place in the README file.
Step 4 – Connecting via SSH
For Windows:
PuTTY – To create a session that you can connect to later do the following.
1. Double click on putty.exe in whatever directory it was downloaded to. A pop-up window will appear.
2. To load the default terminal emulation, color, etc. settings, Click on the “Default Settings”, and then click Load. The “Saved Sessions” and “Host name (or IP address)” boxes should be blank, the Port text box should say 23, and the Telnet Protocol Radio button should be selected.
3. Type in the IP address or the host name, if your name resolution scheme works, of the machine you wish to connect to in the “Host Name (or IP Address)” block, click the “SSH” radio button, (You should see the port change to 22).
4. To save name this session, type an appropriate name in the “Saved Sessions” text box, then click Save. You should see the name you just entered appear in the list of “Saved Sessions”.
5. To start this session, either click once on the name of the saved session, and then click “Open”. Or, Double click on the name of the saved session in the Saved Sessions list box. If this is the first time you have connected to this host, a Security Alert will appear asking if you trust this host, click Yes to add this hosts key to Putty’s server cache. Click “Yes”. In the SSH window, that prompts for username, supply the login and password provided by your instructor.
If this does not work, try to ping the host again as in step 1. If you can ping the remote machine, but cannot connect to it using PuTTY, something at your site (like a firewall) is preventing you from using IP port 22. Contact your network administrator, or ISP for assistance.
For Solaris:
SSH -- You can use SSH commands in place of the telnet, rsh, or ftp commands to connect to any host that has the running the sshd daemon. *See the miscellaneous section for pathname information. Following is the ssh command’s syntax. Useful commonly used switches are –l user, and –v. Switches we will use are,–L listen-port:host:port, -C, and –g. See below for what the switches mean.
#ssh
Usage: ssh [options] host [command]
Options:
-l user Log in using this user name.
-n Redirect input from /dev/null.
-F config Config file (default: ~/.ssh/config).
-A Enable authentication agent forwarding.
-a Disable authentication agent forwarding (default).
-X Enable X11 connection forwarding.
-x Disable X11 connection forwarding (default).
-i file Identity for public key authentication (default: ~/.ssh/identity)
-t Tty; allocate a tty even if command is given.
-T Do not allocate a tty.
-v Verbose; display verbose debugging messages.
Multiple -v increases verbosity.
-V Display version number only.
-P Don't allocate a privileged port.
-q Quiet; don't display any warning messages.
-f Fork into background after authentication.
-e char Set escape character; ``none'' = disable (default: ~).
-c cipher Select encryption algorithm
-m macs Specify MAC algorithms for protocol version 2.
-p port Connect to this port. Server must be on the same port.
-L listen-port:host:port Forward local port to remote address
-R listen-port:host:port Forward remote port to local address
These cause ssh to listen for connections on a port, and
forward them to the other side by connecting to host:port.
-D port Enable dynamic application-level port forwarding.
-C Enable compression.
-N Do not execute a shell or command.
-g Allow remote hosts to connect to forwarded ports.
-1 Force protocol version 1.
-2 Force protocol version 2.
-4 Use IPv4 only.
-6 Use IPv6 only.
-o 'option' Process the option as if it was read from a configuration file.
-s Invoke command (mandatory) as SSH2 subsystem.
-b addr Local IP address.
You may use a hostname, or an IP address to designate what host you wish to connect to. In the following examples, replace the xxx with the specific IP number of the host you are assigned. *See the miscellaneous section for a list of STS classroom IP addresses and hostnames.
You will be connecting to the STS machine as the root user. This level of access is required to add software, and configure the STS host. If you are root on your own host, you can simply type:
# ssh 207.228.42.xxx
If you are not the root user, you will need to use the –l switch to designate that you wish to connect as a user other than yourself. Type:
$ ssh –l root 207.228.42.xxx
If this is the first time the client has connected to the server, you'll be asked if you want to accept the encryption key, simply type "yes" (most SSH versions demand that you type the word, not just "y"), then supply the password provided by your instructor and you should be left at an interactive command prompt. The interactive session gives you full access to the host machine, in the same manner than a telnet or rsh session would.
To transfer files to and from the STS host, there are two options. These are scp, which has similar syntax and functionality as rcp, and sftp which gives you a secure “ftp like” interactive session with the STS host. For secure sftp access to the STS host, as the root user on your local host, type:
# sftp 207.228.42.xxx
If you are not the root user, you will need to indicate that you wish to connect as a user other than yourself by typing the following:
$ sftp root@207.228.42.xxx
Step 4 – Starting and customizing a VNC server session.
VNC allows users connecting from a remote location GUI access to a local host. Each host can have multiple VNC servers running on it, so you'll need to identify which server to connect to. This is done specifying the port + session number of the server in the vncviewer dialog box or command. The VNC server application runs on port 5900.
Each time you start the vncserver session on the STS host, the session number will be echoed back to the screen. To start a vncserver session, follow these directions:
Connect to the STS host using an ssh command, or putty as specified above:
Start the vncserver by typing:
# vncserver
After a brief pause, a message saying “New ‘X’ desktop is hostname:y”, followed by a log message. Note the value of ‘y’. Leave this terminal window open.
For example, if one vncserver is already running on the host you logged into, when you start a vncserver session, you will get something like:
New 'X' desktop is starfish:2
Starting applications specified in //.vnc/xstartup
Log file is //.vnc/starfish:2.log
Then the port number used by that server is 5902. Generally, you will only need to run one vncserver session. If only one vncserver session is running, the number will be 1. This is the most common case, since you have complete control over the STS host, you can start, or stop as many vncservers as you wish. When you start a VNC server session, it will become a daemon, and run in the background. If you break the connection of the terminal that initiated the connection, the VNC server session will continue to run in the background.
Once you connect to your VNC server after following the directions in the next section, you will notice that the connection is not as fast as sitting at the host console in Reno, NV. This is expected. The added overhead of encrypting packets for secure transmission, network bandwidth and host speed at your site, as well as the STS site, the physical proximity of your location to our servers in Reno, NV, and the limitations of the public internet all contribute to performance limitations you may experience in your GUI connection.
In addition to this, there are several contributing factors outlined in detail on the VNC FAQ dealing with improving performance that will enable you to enhance your viewing experience. See http://www.uk.research.att.com/vnc/faq.html#q51 for details. This link indicates that in addition to making the background color of your desktop a single color, decreasing your color depth and resolution will help improve the performance of your connection.
The default color depth and resolution for the vncserver is 16-bit color, and 1024x768 screen resolution. This can be adjusted on the command line. The syntax for the vncserver command is shown by typing:
# vncserver -help
usage: vncserver [:<number>] [-name <desktop-name>] [-depth <depth>]
[-geometry <width>x<height>]
[-pixelformat rgbNNN|bgrNNN]
<Xvnc-options>...
vncserver -kill <X-display>
If you wanted to change you vncserver session to run 8 bit color, and at 800x600 screen resolution you would type:
# vncserver –depth 8 –geometry 800x600
Once you have a vncserver session, and you want to kill it, you can either do a process listing, look for the pid, and kill it, use pkill, or if you wish to kill the first vnc server session you started, type:
# vncserver –kill :1
The vncserver application also comes with a small webserver that should load when the vncserver application is started. It will not load if the java class library is installed. *See the VNC installation section. The web server runs on port 58XX where XX is the number of the display. This is similar to the way that the native viewer runs on 5900 + session number. The web server allows you to download the java client and view the desktop through a web browser. Details of this connection are not covered in this document.
The VNC Frequently Asked Questions site located at: http://www.uk.research.att.com/vnc/faq.html. This will answer most of your questions about VNC.
Step 5 – Setting up port forwarding through an SSH tunnel.
You will need to use SSH and VNC together in order to get a GUI of hosts at STS. SSH contains a comprehensive set of tools and features that allow one to do data compression, port forwarding (including X11 packets), use several types of authentication, including a public key cryptography scheme over several different types of encryption algorithms, and currently has two different protocol versions. The OpenSSH version we are using supports protocol versions 1 and 2.
In our case, we will need to use port forwarding, and optionally compression, to connect to hosts at STS from a remote location.
Initially, contact the classroom server as you did before with an SSH command or putty, and start the vncserver daemon. Notice what server number you're given. For our example, we will assume that the vncserver is running on the host “starfish”, and the server session number is “1”. After starting the server, one would expect to see:
New 'X' desktop is starfish:1
You can have several simultaneous ssh connections with the STS host. Whatever connection starts the VNC server connection does not necessarily have to be the one that connects to the VNC server. Keep in mind that each ssh connection uses system resources of the host you are connecting to.
To remotely view a VNC server session on a host at STS, you will need to use ssh's port forwarding features. When you open up the SSH session with the STS host, you will specify that all the packets sent to an arbitrary port of your local host be forwarded to a specific port on the STS host. When you open VNC, you direct it to connect to this local port you have specified. SSH creates a socket, and using the encrypted SSH session as a “tunnel”, your VNC request is sent to port 5901 on the STS host. This is done differently using the Solaris “command line interface” than it is done using the Windows program putty. Since VNC expects ports in the range 5900, it can abbreviate a 590X port number to X.
*See Miscellaneous section for information about picking an arbitrary local port, and information about the vncviewers interpretation of the port number.
For Solaris:
In this example, for readability we are connecting to host “starfish”. Depending on the name resolution method employed by the machine you are connecting from, you may need to use the IP address of the machine. *See miscellaneous section. Connect to the STS host using port forwarding and compression. Again, if you are not root on your local host you will need to add the –l root switch to indicate that you wish to connect as root. The syntax of how to specify a local port to be forwarded to a remote host and port is as follows:
# ssh -L <arbitrary local port>:<STS host>:5901 -C –g <STS host>
For example, if you had added the host starfish to your local hosts file, and you chose port 5905, as your arbitrary local port, you would type the following command on the your local client:
# ssh -L 5905:starfish:5901 -C –g starfish
In this command, -L tells SSH that the port on the local client should be forwarded to the port on the remote host. 5905 is an arbitrary local port, starfish is the host to connect to, and 5901 is the VNC server port on starfish that we are interested in. The -C flag tells SSH to use data compression, the –g flag allows remote hosts to connect to the forwarded port, and starfish is the hostname of the server to connect to.
Basically, we're saying that if anything tries to access port 5905 on the local machine, forward it to port 5901 on starfish. Compression is recommended for low bandwidth connections such as modems, or over very large physical distances. In a local lan, compression is not recommended. Whether or not compression will improve your performance depends on many factors. The use of compression in some cases can actually hurt performance. You might try your connection with and without compression and see what works best. *See the miscellaneous section for further information.
For Windows:
The same information must be conveyed to the ssh client command that you run when you use putty. It is done in a different way, using options within the putty command. To use putty to effectively run the same ssh command as is listed in the Solaris section do the following:
Open up a putty window as you did before by double clicking on the putty.exe icon.
If you have a session for your host saved, load that session. I.e. Click on the saved session name, and click load. This should put a hostname or an IP address in the Host Name (or IP address) field. If you do not have a session saved, follow the instructions outlined above in step 4.
Once you have loaded your previous session, save a new session name appending –portforward, or something appropriate to the end of the name. This is to differentiate it from the normal ssh session. Do this by clicking at the end of your session name in the Saved Sessions text box, and typing in appropriate text to the session name. Then save this session name by clicking Save. Another session name should appear in the Saved Sessions list box.
Under the SSH category in the left hand column, click on “Tunnels”. A different menu will show up in the right hand side of the configuration window.
Towards the bottom of the menu, click in the Source Port text box, and enter your arbitrary local port. *See Miscellaneous section for picking a port. We will use 5905. Then click in the Destination Text box, and enter the hostname or IP address, followed by the port number you wish to forward your local port to. In this example, enter starfish:5901. The Local Radial button should be checked. Now click Add. You should see L5905 starfish:5901 appear in the Forwarded Ports list box. If you made a mistake, you can click on it and remove it, then re-add it.
Now click on the Session category in the left hand column. Then save your Port forwarded session by clicking Save.
Step 6 – View a local graphical user interface of the remote STS host using VNC.
Normally, when running the vncviewer application, you would specify that you wish to connect to the host that is running the vncserver in the text box. – In the case of our example above, this would normally be starfish:1, or starfish:5901 *See Miscellaneous section for further information. However, since we are forwarding all requests on our local port to 5901 on the remote STS host, we will need to connect to localhost. This is a special name for the local server. This process is slightly different when using a Solaris client and a Windows client.
For Windows:
Double click on the VNC Viewer icon. Type localhost:5 in the dialog box. Since VNC expects to connect to a port in the 5900 range, our arbitrary port of 5905 is shortened to 5. In testing, it has been determined that Hextile format, and Copyrect encoding have improved performance. You may leave the default values, but our recommendation is to choose the following:
Click “Options”. Select Hextile format, and “Use Copyrect encoding”. If you have specified that your server is using 8-bit color depth, you can select “Use 8 bit colour”. Also, if you wish to emulate 3 buttons with your mouse, you can specify that in the check box. Finally if you wish to run VNC in full screen mode, you may check that. Close the “Options” window, and click “OK”.
If you are prompted for a password, this means that you have successfully connected to the vncserver on the STS host. You will be prompted for the password that you will be informed of by your instructor. Enter the password, and click OK. – You should see the dt window manager pop up as if you were in front of the Solaris host.
Do not exit the session by clicking exit on the dt menu bar. Doing so could potentially cause problems with the STS host. To close your vnc session, simply click the “X” in the upper right hand corner as you would any other Windows program. Your vncserver session, and all the programs running in the session will remain open even if you close the vncviewer window. This is so that you can re-connect to an existing session later, which is particularly useful if you start interactive processes like ufsdump. Your programs will remain running until you close or until you kill the vncserver session.
For Solaris:
To use the vncviewer on Solaris, you will connect using the same options, and making the same choices as you did connecting from a Windows machine. However, the vncviewer application is initiated using a command on the command line. Following is the usage syntax from the vncviewer application.
#vncviewer -help
VNC viewer version 3.3.6 - built Nov 26 2002 15:44:38
Copyright (C) 2002 RealVNC Ltd.
Copyright (C) 1994-2000 AT&T Laboratories Cambridge.
See http://www.realvnc.com for information on VNC.
usage: vncviewer [<options>] <host>:<display#>
vncviewer [<options>] -listen [<display#>]
<options> are standard Xt options, or:
-shared
-viewonly
-fullscreen
-passwd <passwd-file>
-noauto
-encodings <encoding-list> (e.g. "raw copyrect")
-bgr233
-owncmap
-truecolour
-depth <depth>
You have already setup your SSH tunnel to forward your local 5905 port to port 5901 on starfish. To have vncviewer connect through your local port 5905 through SSH to starfish's port 5901. Open up your favorite terminal window (xterm, dtterm, etc.) and type:
# ./vncviewer -depth 16 -encoding "copyrect hextile" localhost:5
This will connect to your local port 5905, give you a color depth of 16, and use the copyrect hextile encoding as specified above. You may wish to experiment with other options.
For information on using the Java VNC client, see the Miscellaneous section
Miscellaneous
Name Resolution:
Name resolution of hosts within the simonsontech.com domain is available on the public Internet via our name servers residing in Reno, NV. In all the above examples, you can use the hostname designated by your instructor plus the fully qualified domain name to access the STS hosts. If name resolution does not work, it may be due to network issues at your site, or our DNS server. If you have name resolution problems, you may wish to add a local host entry on your machine to point directly to a simonsontech.com machine. A list of the hosts that are available at STS is included below. To add a local host entry to your workstation, do the following:
For Solaris:
Edit the /etc/inet/hosts file, add one of the entries below. Save the file, and test the connection by typing ping <hostname>.
For Windows:
If you are using Windows 2000, or Windows XP, the local hosts file lives in C:\windows\system32\drivers\etc. If you are using Windows 9.x, the hosts file should live in C:\windows. Edit this file; add one of the entries below. Save the file, and test the connection by typing ping <hostname>.
SSH location.
For Solaris:
If you installed the sunfreeware version of openssh, ssh will be in /usr/local/bin. Depending on the version of Solaris, and the SSH package, the ssh binary may be located somewhere else, like /usr/bin, or /opt/sfw/bin. You may need to add the directory of the ssh binary to your PATH variable.
For Windows:
Wherever you save the putty binary to will be the location that you need to run it from. Many people have the “My Documents” folder as the default location for saving items downloaded on the Internet. Other common places are the Desktop, or the “My Downloads” folders. Make sure to pay attention to where you save putty.exe on your hard drive. If you can’t find it, you may wish to “Do a search”. This can be accomplished by clicking the “Start” button, clicking search, then clicking “For files or folders”. Once you have the search window pop up, enter putty.exe in the dialog box, and click “Search Now”.
Local port selection:
When you pick a port on your local host that you wish to forward to the VNC server port on the STS host, you should pick a port number between 1024 and 65535. Ports below 1024 are considered “privileged” and the maximum port number on a Solaris machine is 65535. Also, make sure to pick a port that does not conflict with running services on your local host. If you choose a port that something is already running on, you may not be able to forward the port, and additionally may cause problems with that locally running service.
In all the examples above, we choose the random port as 5905. Since we chose this port, we could abbreviate this port as 5, since the vncviewer expects to connect to a port in the 5900 range. You could have easily typed 5905 in place of 5 for any of the examples. Or, you could have chosen a port like 60002, and specified that in the vncviewer application, or command.
Compression:
Although the –C switch is supported in SSH protocol version 1 and 2, the CompressionLevel setting in the sshd_config file is only supported with SSH version 1. Compression is on by default.
Vncviewer Java Server:
VNC accepts http requests at ports in the 5800 range by default. That could allow you to connect using a web-browser. Open up a Java enabled browser, and open a session to , where X is the session number. Port forwarding through SSH is not supported by the Java client. For further information see: http://www.realvnc.com/javavncviewer.html.
Console Access:
In order to gain console access to machines designated as workstations for a class at Simonson Technologies, one must do the following.
1. Read the "Instructions for accessing a UNIX host at Simonson Technology Services using SSH and VNC". Then make sure that all requirements are met, follow steps one through three to check your connection, download the connectivity software putty, and install it.
2. Using the putty program, create a new session to the host seaweed.simonsontech.net (207.228.42.33).
3. Log into seaweed as the user console. Your instructor will give you the password.
4. Select the number corresponding to the host that you were assigned and hit enter.
5. You will see the machine connect to the terminal concentrator, then prompt you for the "Escape character".
6. Hit enter to see the console prompt, and login to the console with the password your instructor gave you.
Following is an example:
[rmadison@calypso rmadison]$ ssh -l console seaweed
console@seaweed's password:
Last login: Mon Jan 13 10:57:27 2003 from calypso.simonso
Sun Microsystems Inc. SunOS 5.9 Generic May 2002
#################Console Connection Menu#################
# #
# Enter the number next to the action to take or the #
# host to connect with, followed the carriage return. #
# #
# 1. 207.228.42.129 starfish #
# 2. 207.228.42.130 urchin #
# 3. 207.228.42.131 seal #
# 4. 207.228.42.132 dolphin #
# 5. 207.228.42.133 shark #
# 6. 207.228.42.134 stingray #
# 7. 207.228.42.135 coral #
# 8. 207.228.42.136 eel #
# 9. 207.228.42.137 sunfish #
# 10. 207.228.42.138 whale #
# 11. 207.228.42.139 jellyfish #
# 12. 207.228.42.140 seahorse #
# 13. 207.228.42.141 squid #
# 14. 207.228.42.142 turtle #
# 15. Exit #
#########################################################
Enter number: > 1
Trying 207.228.42.252...
Connected to 207.228.42.252.
Escape character is '^]'.
starfish console login:
/etc/hosts file for the STS student machines
# #Classroom Workstations # 207.228.42.129 starfish # TC Port 5008 207.228.42.130 urchin # TC Port 5007 207.228.42.131 seal # TC Port 5004 207.228.42.132 dolphin # TC Port 5003 207.228.42.133 shark # TC Port 5011 207.228.42.134 stingray # TC Port 5012 207.228.42.135 coral # TC Port 5006 207.228.42.136 eel # TC Port 5005 207.228.42.137 sunfish # TC Port 5016 207.228.42.138 whale # TC Port 5015 207.228.42.139 jellyfish # TC Port 5009 207.228.42.140 seahorse # TC Port 5010 207.228.42.141 squid # TC Port 5014 207.228.42.142 turtle # TC Port 5013