This article provides information about the minimum requirements for using Dynamic VPN using Pulse Secure Desktop Client
The Pulse Secure Desktop Client is unable to establish a connection to the SRX
It is usually the case that a connection cannot be established because the minimum requirements for the Pulse Secure Desktop Client and the SRX device are not met.
The minimum requirements for the client and the SRX device are listed below. Check to see if your client and SRX device meet the minimum requirements.
The Dynamic VPN feature is supported by the following SRX devices and Junos releases:
Dynamic VPN is a licensed feature. By default, a two-user evaluation license is provided (free of charge) on SRX devices and it does not expire. When more than two users have to connect concurrently, a license is required. For license ordering information, refer to the following datasheet: http://www.juniper.net/us/en/local/pdf/datasheets/1000281-en.pdf .
If your client and SRX device meet the minimum requirements but you are still having issues establishing a connection, see KB17220 - Resolution Guide - SRX - Troubleshoot Pulse VPN connections to SRX [juniper.net] .