User Interface Getting Started
COMMUNICATING
In order to configure and program the JNIOR you will need to communicate
with it. The JNIOR has no keyboard or display interface. There are ways to
interact with the unit both serially and through the network.
NETWORK ACCESS
In order to fully interact with the JNIOR and use its WebUI you must properly
configure the unit to operate on the network. JNIORs are now being shipped
from the factory with Dynamic Host Configuration Protocol (DHCP) enabled. With
a network supporting DHCP the JNIOR will obtain a valid IP address and
automatically configure itself properly for the network. You will still
need to determine the IP address that it has been assigned.
One unique method uses the orange status LED. If you know the first 3 octets
of the IP addressing used by the network you can determine the forth octet and
therefore the full IP address assigned to the JNIOR. Connect the JNIOR to the
network and power it up. After a couple of minutes disconnect the network
connection leaving the unit powered. The status LED will flash the digits of
the last octet in Morse Code! See the
MORSE_CODE reference for the digit
patterns.
You can download the
JNIOR Support Tool from the Downloads area under
Support on the website
jnior.com . The Support Tool uses the
Beacon
Protocol to communicate with JNIORs on the local network segment. The active
JNIORs on the network are listed under the Beacon tab. This protocol does not
require that the JNIOR have a valid network configuration. A JNIOR even if
configured for a foreign network will appear in the list. You can right-click
on a JNIOR and select Configure and IP Configuration to establish settings.
Once the IP Address of a JNIOR (properly configured for the network) is known
you may enter the following URL in a browser to activate the Dynamic
Configuration Pages WebUI.
http://[IP Address]
The WebUI is distributed as the file
/flash/www/config.zip and the default
setting of the Registry Key
/WebServer/Path is
/flash/www/config . This
allows the simple use of the IP address (or hostname) in the URL to locate
the supplied WebUI.
If the JNIOR has been previously configured to support a custom Website you
may bypass that site and reach the WebUI with the following URL.
http://[IP Address]/config
The JNIOR supports the HTTPS:// secure protocol as well.
FINDING YOUR JNIOR ON THE NETWORK
From a Windows system located on the same network leg you may access the
JNIOR using its Hostname. Even after you edit the hostname as might be
appropriate for your situation you may use the new name or the unit's
Birth Name. By default the JNIOR is shipped with its hostname being a
combination of the characters 'jr' followed by the unit's serial number.
We refer to this as its birth name.
This will also work from Linux systems when the Wins name resolution has
been enabled.
For instance, referring to the label on the rear of a JNIOR we see that its
serial number is 615010258. We can enter the following URL:
http://jr615010258/
In most cases this will open the WebUI for that JNIOR. The name resolution
systems vary from network to network and computer to computer. So your
experience may vary. If you redefine the
hostname the above will still
work and if you replace the birth name with your new host name that should
work too. Note that there are constraints on the format for a valid host
name. The JNIOR may let you define a name not meeting those requirements
and therefore won't work in this context.
Typically a device like the JNIOR where you need to go to it with your
browser or other network function is termed a 'server'. Servers would
normally be assigned a fixed IP Address by those managing the network.
If you need to configure a fixed IP address you may use these techniques
to first access the unit and then make the changes using the
ipconfig
command.
The
Support Tool also provides access to any JNIOR with an unknown IP
address or even a JNIOR with an incorrect network configuration. This tool
can assist you in configuring JNIORs for other networks or in working with
those that have been brought in from a remote site.
COMMAND LINE INTERFACE (CLI)
The Command Line Interface (CLI) is the basic access point to any operating
system. Windows provides a Command Prompt that originated from MS-DOS. Linux
based systems rely upon a terminal interface (Ctrl-Alt-T). The JNIOR is no
different and JANOS uses a CLI that is modelled closely after both of those.
Users familiar with either interface will feel at home.
There are many points of access to the command line. In the absence of the
network a serial cable may be used as describe in the next section. Over the
network the CLI is available as the Console tab in the WebUI, through a
Telnet connection, and now also with the Secure Shell (SSH) protocol.
SECURE SHELL (SSH)
JANOS now supports SSH. This protocol offers a cryptographically secure
connection the the JNIOR. It can offer functionality beyond simple terminal
access to the CLI and is therefore worth a little more discussion.
Currently the JANOS SSH implementation is limited and may not be functional
with older SSH client packages. It should work with most fully updated
client packages. The SSH command is available from the Windows 10 command
prompt; It is functionald from Linux terminals; And, you can use the popular
PuTTY program, among others, for an SSH connection.
The typical command syntax from a Linux terminal looks like:
ssh jnior@10.0.0.239
This makes an SSH connection using the username 'jnior' (by default an
Administrator on any JNIOR). On first access to a JNIOR you will see a
message like this:
The authenticity of host '10.0.0.239 (10.0.0.239)' can't be established.
ED25519 key fingerprint is SHA256:idqhzbRVeCP+fVldu20xNWE3kfr/AhSEoenYLTrywwo.
Are you sure you want to continue connecting (yes/no/[fingerprint])?
If you approve by answering 'yes' the system will store this fingerprint
and not confront you again unless this does not remain consistent. After
answering in the affirmative it proceeds:
Warning: Permanently added '10.0.0.239' (ED25519) to the list of known hosts.
jnior@10.0.0.239's password:
Here you enter the unit's password (also 'jnior' if default) and the connection
is made.
XTERM SUPPORT
One advantage of the SSH connection is support for dynamic screen dimensions.
The screen width and height is conveyed on connection and updated whenever
you resize the associated window. In addition the XTERM terminal supports
color characters. These are new terminal capabilities for JANOS.
As a result during an SSH connection JANOS will highlight the command
prompt in green and render errors in some places in red. Some commands
can utilize a greater screen width and will adjust their output accordingly.
The
EDIT editor when used in an SSH session will expand to utilize the entire
screen area both in width and height.
PUBLIC KEY AUTHENTICATION
While you typically authenticate by supplying the valid password for the
login account, SSH offers the ability to bind a client computer to the
JNIOR using a key pair. In order to do so your computer needs to have such
a key pair. This is typically created using the following command:
ssh-keygen [options]
This is executed on the client computer and options may not be needed. If
the command asks you to overwrite an existing key, it is probably a good idea
to leave the original in place and simply abort the command. That is proof
that a key has already been generated. It may already be in use with other
connections. If you overwrite the key you will need to resubmit the new
key for all other uses.
Once you know there is an SSH key pair, you can submit the public part of
the key to the JNIOR. If the this is accepted it will serve as authentication
and bypass the need for password entry. The procedure for doing this varies
from server to server. The JNIOR provides a built-in command for this purpose.
When connection to other Windows or Linux systems the 'ssh-copy-id' command
may be executed on the client comupter. This may perform the necessary steps
to submit the key. With JANOS you would execute the 'copy-id' command on the
remote JNIOR as follows:
ssh jnior@10.0.0.239 copy-id
jnior@10.0.0.239's password:
public key successfully added
You will need to authenticate with a valid password. In the background the
SSH protocol would have attempted to authenticate using the public key. This
built-in command then may add the key to the user's authorized_keys file.
Once the client computers public key has been accepted and recorded you may
reconnect using SSH without the password requirement from the system. Behind
the scenes your connection is authenticated as you prove that you do have the
private part of the key matching the recorded public key.
While this is a convenience and veryu helpful in executing remote commands,
there is complicated cryptography in use which cost in computing time. This
type of authentication can be slower than having to entry the password.
REMOTE COMMAND EXECUTION
While SSH allows you to establish a secure connection to a JNIOR and then to
manage that unit through the Command Line Interface, it can also be used
to remotely execute commands. Generally the SSH client will process any
additional text on its command line as an individual command to be executed
on the remote server. For instance if you are able to connect without need
for the password entry the following command will simple close ROUT 1 (relay
output 1) on the remote JNIOR and return back to the local prompt.
ssh jnior@10.0.0.135 jrmon -x c1
This would execute the
JRMON command on the remote JNIOR thereby closing the
relay.
It is important to note that this is not an acceptable replacement for an
application to toggle the remote relay using, for instance, the JMP Protocol.
Due to the overhead in making the secure SSH connection the execution of the
above command can take several seconds. An application using the appropriate
protocol however can close that relay within milliseconds. Also, the above
command provides no feedback that any relay had actually been activated.
An application would have immediate confirmation and would have the opportunity
to address any error situation.
SERIAL ACCESS
In the absence of a network connection you can reach the Command Line
Interface (CLI) or Console through the COM serial port. A USB-to-Serial
adapter may be used as PCs these days do not provide serial ports. The
communications parameters are 115,200 Baud, 8 Data Bits, 1 Stop Bit and No
Parity.
The
IPCONFIG command at the command line can be used to determine and
alter the IP configuration of the JNIOR. This command may be necessary in
establishing proper network addressing if DHCP or the Support Tool cannot
be used. For example: The JNIOR may be connected to the network using a
cellular modem or other wireless approach not supporting the broadcast
required by the Beacon protocol.
The CLI is quite powerful in many ways and not just for configuration although,
the network is still required for transferring files either on to, or off of,
the device.
NOTES
A network cable can often be used to connect the JNIOR directly to a PC.
The Support Tool running on the PC will locate the JNIOR and allow
you to configure the unit.
The Telnet application built in to the Support Tool can be used for serial
communications. After opening the Telnet tool the
Connect button at the
bottom offers the serial option.
SEE ALSO
HELP Topics:
MORSE_CODE,
BEACON,
NETWORK,
COM_SERIAL,
IPCONFIG
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