Juniper Screenos VPN client (NCP Secure Client)

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Juniper Networks

If you require an IPSEC VPN Client for ScreenOS – Juniper Partner with NCP. Its called  NCP Secure Client – Juniper Edition

The following is a Juniper KB article about the product.

NCP Secure Client – Juniper Edition FAQ

The original version of the Juniper KB article below is found here:



Frequently Asked Questions (FAQ) for the NCP Secure Client – Juniper Edition.

Problem or Goal:

  • Where can I find a VPN client for Juniper/Netscreen devices.
  • Where can I find a VPN client for Windows 7 or Windows Vista?
  • Can I still buy Netscreen Remote?

Juniper officially announced plans to EOL NS-Remote on June 30, 2009.

A possible remote VPN alternative is the NCP Secure Client.  Juniper has entered into a reference sale arrangement with a third party company, NCP engineering, Inc (, whose client has been validated to work with Juniper gateways running ScreenOS.

This article addresses some frequently asked questions related to NCP and NetScreen-Remote (also referred to as NS-Remote and NSR).


Refer to the Q & A below, which is divided up into two sections:  NCP Related Questions and IPSec and NS-Remote Related Questions.

NCP Related Questions

Q: How does JTAC support work with NCP?
A: This is a reference sale, meaning the customer purchases both the product and support from NCP. The advantage of using NCP is that Juniper does validate the client and provides guidance on supported case. JTAC will assist with issues found on the Juniper device. If an issue is found on the NCP side, customers will need to call NCP.
NCP Helpdesk can be contacted at:
  • +49 9119968 0
Q: Is Juniper going to OEM the NCP client?
A: No, this will be a reference-sale arrangement only, with customers and partners buying the client directly from NCP.
Q: Which operating systems are supported by NCP and validated by Juniper?
A: The NCP IPsec VPN clients validated by Juniper are:
  • Windows XP (32-and 64-bit)
  • Windows Vista (32- and 64-bit)
  • Windows 7 (32- and 64-bit)
Q: Will the NCP client and NS-Remote client work with the same Juniper IPSec gateway simultaneously?
A: Yes.
Q: Where can I find additional information on the NCP client?
Q: What support services are available from NCP?
A: NCP includes service with every NCP IPsec client purchased.
Q. Where can I get the Secure Client Juniper Edition of NCP?
A. Only Juniper distributors listed under can purchase the NCP Secure Client Juniper Edition from NCP directly. End users and resellers are requested to contact their regional Juniper distributor to obtain the Juniper edition of the NCP Secure client.
Q: Which Juniper IPSec gateways will work with the NCP clients?
A: All ScreenOS gateways currently supported by NS-Remote are also supported by the NCP client. Support for Branch and High-End SRX gateways is forthcoming.


IPsec and NS-Remote Related Questions

Q: What other VPN options do customers have for remote access connectivity?
A: Consider moving to Juniper’s SSL VPN solution.
For customers with more than 50 endpoints, SSL VPN is Juniper’s recommended alternative to IPSec remote clients. SSL VPN appliances effectively address the challenge of anytime, anywhere, secure remote access to users. The market leading Juniper Secure Access (SA) Series SSL VPN Appliances ( provide secure remote mobile access to employees, partners, and customers from a single platform. These solutions offer the following advantages over using IPSec remote clients:
  • Only a web-browser and Internet connection are needed for user access
  • There is no client software to install, maintain, or configure
  • All devices are subject to comprehensive security checks before access is granted
  • You have granular access control of users to particular resources
  • Secure remote access facilitates business continuity during unplanned events like pandemics or natural disasters
  • Rich logging and auditing reports ease regulatory compliance efforts
Q: Can customers receive refunds for NS-Remote products purchased last quarter?
A: Juniper does not issue refunds for products already purchased. We value our customers immensely and want to work with them to ensure that their existing products are supported and that they have adequate time for a smooth migration.

Q: What IPSec VPN options are available for existing NS-Remote customers?
A: Operating systems like Windows Vista and Windows 7 have a built-in IPSec client. For supported deployment scenarios, built-in IPSec clients have the added advantage of eliminating the need to install and maintain a separate client application.

Alternatively, Juniper has entered into a reference sale arrangement with a third party company, NCP engineering, Inc. (, whose client has been validated to work with Juniper gateways running ScreenOS.
Q: Which Microsoft operating systems with built-in IPSec clients will be supported by Juniper?
A: Our general testing of the Microsoft operating systems has shown limited success when working with Juniper IPSec gateways. Native Microsoft IPSec clients were evaluated to determine interoperability and support for termination on ScreenOS firewalls. This section outlines the different tests performed.

Operating systems evaluated: Windows XP (32-bit), Windows Vista (32- and 64-bit) and Windows 7 (32-bit)

Windows VPN modes tested: Windows primarily supports remote connections by performing L2TP over IPSec. It does support native IPSec, but it is not the primary way to configure VPNs in Windows. Both modes were tested here for this trial. The results were the same across all four platforms.

L2TP over IPSec: L2TP over IPSec encapsulates user traffic within the L2TP protocol, which is then encrypted with IPSec; since L2TP offers no native encryption. Windows supports two modes of remote access through their primary remote access component. This is L2TP over IPSec and PPTP (not supported by ScreenOS or Junos).

The configuration of the Windows client to a ScreenOS Firewall was successful but with several notable caveats that will limit the use cases it can address. First, L2TP over IPSec does not support NAT-T (at least not with interoperability with the ScreenOS platforms) so this essentially limits it to only connections without NAT. Next, it can only function with ScreenOS by authenticating with Certificates, and will not properly support preshared key authentication based on our testing. This has to do with an inability to properly authenticate the identity with anything except IP address IKE ID. Due to these limitations, it was deemed that L2TP over IPSec can be used if for certain use cases, but would not be a direct replacement for NS-Remote.

Native IPSec: Windows lets you configure true IPSec VPN tunnels natively with IPSec components built into Windows. This configuration is much more challenging than configuring L2TP, as it requires numerous values to be defined primarily through a Microsoft management console configuration. There were several noted limitations on configuring this method. First, the native Windows IPSec does not support XAuth, so this would make it very difficult to implement in a large scalable fashion. Next, support for NAT-T requires modifying the registry. By default, the IPSec client tries to create a VPN tunnel wherever possible (so even if the end system is within the network it will try to create an IPSec tunnel.) This can be undesirable for users who use their machine both locally in the LAN as well as remotely. Additional customization, such as scripting, can be used to improve the behavior

Conclusion: Based on thorough testing of the Windows L2TP over IPSec and native IPSec clients against ScreenOS, the testing engineers concluded that the native clients have not evolved much and that third-party IPSec clients offer a richer feature set supporting a broader range of use cases. Although Microsoft native clients can be used in limited cases, other alternatives should be sought out that can provide standard IPSec capabilities with robust encryption features, XAuth, NAT-T, PSK and certificate authentication, and wide platform support.

The following Knowledge Base items are also available:

KB17364 – Example configuration of NCP Client

KB10939 – Configuring a dial-up VPN using Windows XP client with L2TP over IPSec (without NetScreen-Remote)

KB16075 – Configuring a dial-up VPN using Windows 7 client with L2TP over IPSec (without NetScreen-Remote)