Desktop and Mobile Systems Support

VPN Client for Linux

Option 1:   Java Free Connection Method

Option 2:  Below is information on how to install the 32 bit Network Connect client on 64 bit Linux platforms.


 From 7.3 onwards, Juniper SA devices support 64-bit Linux (Redhat, OpenSuse, and Ubuntu) for Network Connect.

 Note: Juniper made changes in the existing 32 bit Network Connect client to launch it on 64 bit Linux platforms, which has all the necessary components/dependencies for 32 bit NC to work.

 To launch NC on 64 bit Linux, you need to have the 64 bit Mozilla Firefox browser, with the Java plug-in already configured. You can use both the Oracle and OpenJDK JRE. If the user installs the OpenJDK JRE, then the version of IcedTea-Web plug-in (java plug-in) should be 1.2 or higher.

Check for and remove existing Java versions

Existing 32-bit javas may be in the alternatives list already, but may not work with the client. Check for them with this command:

update-alternatives --display java

and remove if necessary:

rpm -e java-1.5.0-gcj --nodeps

then proceed with the 32-bit java installation.

Installation procedure

1. Install the 32 bit Java version:

  • 32 bit Java installation (Oracle JRE 6/ Oracle JRE 7, OpenJDK JRE 6/OpenJDK JRE 6):
    • Download jre-7u3-linux-i586.tar.gz and copy it to a folder (for example,/usr/java32).
    • Run the tar –xvf jre-7u3-linux-i586.tar.gz.

2. Update the alternatives link for Java:

  • Use the sudo update-alternatives --install /usr/bin/java java <32 bit java path> command.
  • For example: sudo update-alternatives --install /usr/bin/java java /usr/java32/jre1.7.0_03/bin/java 10.
  • Ensure that the default Java version is still 64 bit. This can be checked by looking at the link currently points to string in the output of the update-alternatives --display java command.
  • If the default Java version is 32 bit, then change it to 64 bit, by using the sudo update-alternatives --config java command.
  • After performing the above steps, alternative links will look as illustrated in the following image (the highlighted rows show both the 32 bit Java path and the default Java version:


Note: If 32 bit Java is installed via package managers, such as apt-get, yum or zypper, the 'alternatives' link may get automatically updated. In such a case, you can skip Step 2.

3. Install the standard 32 bit libraries and components:

  • Ubuntu:
    • sudo apt-get –y install ia32-libs
  • RedHat/Fedora:
    • yum –y install xterm
    • yum –y
    • yum –y
    • yum –y
    • yum –y
    • yum –y
    • yum –y
  • OpenSUSE:
    • zypper install

Connect to the VPN server

Now you can connect to the VPN server and click the start button to launch NC. If the NC launcher applet can find the 32 bit Java path in the alternatives links, NC will successfully launch. Otherwise, the following error message is generated:


 To launch Network Connect via the command line, use the following command:

<java_path> -jar NC.jar -h -u -p [-r ]

-f <ivecertificate_in_der_format> [-l <gui_log_level> [-L <ncsvc_log_level>] [-y -

z <proxy_port> [-s <proxy_username> -a <proxy_password> [-d <proxy_domain>]]]


<java_path> is the path to the 32 bit Java version.


IcedTeaPlugin will display the Start: Applet not initialized error, if the common name (CN) of the VPN's web server certificate does not match with the host name, which is typed in the address bar.

This is not a issue with the Juniper VPN. To resolve this, you can add the common name (CN) in /etc/hosts and access the VPN server via common name; instead of the IP address.