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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 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 and 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 5
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 6
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 7
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. 207.228.42.34 starfish #
# 2. 207.228.42.35 urchin #
# 3. 207.228.42.36 seal #
# 4. 207.228.42.37 dolphin #
# 5. 207.228.42.38 shark #
# 6. 207.228.42.39 stingray #
# 7. 207.228.42.40 coral #
# 8. 207.228.42.41 eel #
# 9. 207.228.42.42 sunfish #
# 10. 207.228.42.43 whale #
# 11. 207.228.42.44 jellyfish #
# 12. 207.228.42.45 seahorse #
# 13. 207.228.42.46 squid #
# 14. 207.228.42.47 turtle #
# 15. Exit #
#########################################################
Enter number: > 1
Trying
207.228.42.48...
Connected to 207.228.42.48.
Escape character is '^]'.
starfish console login:
/etc/hosts file for the STS student machines:
207.228.42.34 starfish # TC Port 8
207.228.42.35 urchin # TC Port 7
207.228.42.36 seal # TC Port 4
207.228.42.37 dolphin # TC Port 3
207.228.42.38 shark # TC Port 11
207.228.42.39 stingray # TC Port 12
207.228.42.40 coral # TC Port 6
207.228.42.41 eel # TC Port 5
207.228.42.42 sunfish # TC Port 16
207.228.42.43 whale # TC Port 15
207.228.42.44 jellyfish # TC Port 9
207.228.42.45 seahorse # TC Port 10
207.228.42.46 squid # TC Port 14
207.228.42.47 turtle # TC Port 13
207.228.42.48 tc-103 # The TC
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