Some time ago, Juniper Networks sold their beloved Junos Pulse SSL VPN, and thus new company called Pulse Secure was created. Which resulted in Pulse Secure client, which is used to establish secure authentication to the (VPN) tunnel.
Since Juniper never supported Linux, it comes as no surprise that successor company client supports every other platform except Linux.
Setting Juniper VPN/Secure Pulse on Linux is pain. Basically, it comes down to using Java applet in web browser or using 3rd party hacks and scripts. Something I refused to accept.
Getting it to work in a web browser
Although, it can be bit confusing on 64 bit architecture, getting VPN access via web browser is simple. You just need to install right packages:
sudo apt-get install icedtea-7-plugin openjdk-7-jre:i386 libstdc++6:i386 lib32z1 lib32ncurses5 libxext6:i386 libxrender1:i386 libxtst6:i386 libxi6:i386