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Zscaler Private Access Just Might Eradicate VPNs

Years ago, when I was still with Yankee Group, a small SSL VPN vendor called Neoteris (acquired by NetScreen, which was subsequently acquired by Juniper Networks) asked me to provide a quote for an upcoming press release. I agreed, and the company sent me one having me say that SSL VPNs would eradicate traditional VPNs. I rolled my eyes at that, and rewrote the quote. I liked SSL VPNs, but IPSec VPNs did a lot of things that they didn't. (Also, I'm very careful never to use words like "eradicate," because older technologies live on for a long time.)

This week I attended cloud network and security vendor Zscaler's first-ever user event, called Zenith, in Las Vegas. Zscaler was one of the early pioneers in cloud security, and while it's taken a while for businesses to believe in the model, it has caught fire of late. Interest in Zscaler, which recently went public, has been as hot as the Vegas sun. For a first-time user event, attendance was strong, at about 600 people, with keynotes from major customers like GE and Siemens and partners such as VMware and AT&T. Given Zscaler's strong relevance to SD-WAN, almost all the major SD-WAN vendors, including VMware VeloCloud, Riverbed, and Silver Peak had booths in the technology showcase. SD-WANs essentially make the Internet the company network and Zscaler shifts the security there.


One of the more interesting products Zscaler highlighted at Zenith is a relatively new one called Zscaler Private Access, or ZPA -- and it has the potential to replace (dare I say "eradicate?") those cumbersome IPSec VPNs that users hate so much. One of the reasons ZPA has a chance to do this where SSL VPNs didn't is that the dynamics of application access have changed. A decade ago the majority of applications were on the company premises, so SSL VPNs provided a slightly smarter way to access a subset of apps. Most businesses weren't going to go through the hassle of replacing their current infrastructure for a slight improvement. Many augmented their current technology, but few replaced it entirely.

Today, the majority of critical business applications such as CRM systems, office productivity, unified communications, contact center and more are in the cloud, so a technology that routes a user into the network just to send it back out doesn't seem optimal, to say the least. To get an understanding of how inefficient this process is, I'll try and illustrate the flow:

  • A user wants access to company resources, so invokes the company's preferred VPN client to connect to the local VPN concentrator.
  • Once connected, the traffic must pass through additional security appliances, such as firewalls, intrusion-prevention systems, internal load balancers, and more. If the user works at a large enterprise, the traffic probably had to traverse global load balancers front-ending the VPN concentrators, adding to the list of appliances.
  • The user gains full network access to company resources, which could have regulatory implications.
  • If the user connected to a remote office, the session must pass over the WAN to the data center, and then out to the Internet.
  • The user is finally able to connect to Office 365, Amazon Web Services, or other cloud service required.
  • That entire sequence then takes place in reverse when sending the data back to the user.

Again... not optimal, to say the least. In developing ZPA, Zscaler rethought remote access in the era of cloud, and architected it on the following four principals:

  1. Remote users should never be placed on the network. Rather, they should be granted application access. With no network access, IP addresses become irrelevant.
  2. Applications are invisible to unauthorized users. If a user's access is compromised, a zero-trust model prevents this leading to an application breach.
  3. Application-level micro-segmentation enables IT to deliver precise policy-based application access to users.
  4. The Internet becomes the new corporate network. Trust no one, and encrypt everything... Fox Mulder would be proud.

Zscaler ZPA contains three components:

  • Zscaler Enforcement Node (ZEN), a customizable cloud-based service that authenticates users, brokering the secure connections between users and applications.
  • Zscaler app (Z-App), a lightweight mobile client that's installed on the users device and makes the request to the application. The Z-App is different than an IPSec client in that it's always running so doesn't need to be invoked when the user requires remote access.
  • App Connector, which sits in front of cloud-based and on-premises apps, listens for application access requests, and connects to the Z-App.

During one of the keynotes, the company did a side-by-side comparison demonstrating its remote access product compared to a more traditional IPsec one, and the results weren't even close. Because the ZPA client is always-on, user access to applications is exactly the same whether the worker is in the office, at a Starbucks, or sitting in the lobby of a hotel. This is key, as with this concept of remote access, in-office access, home access, and all the other types of access needs to go away and simply become known as "access." Traditional access methods make the user the integration point for all the technology, and that's doomed to fail. Zscaler's ZPA fundamentally changes the concept of access as the process of logging in and logging out goes away.

At the show, the company previewed an upcoming enhancement where ZPA could run inside the browser so workers would be able to access company resources when sitting at a shared machine or other device where the client can't be installed. This is one of the big challenges associated with running VPN clients, but Zscaler appears to have solved that problem.

The fact that users aren't connected via an open tunnel has big security implications. A worker sitting in a coffee shop connected to free Wi-Fi service with a VPN client running is giving unfettered access to their company network to anyone that might breach their computer. The problem with free Wi-Fi is the owner is unknown. It might be the establishment, but it could be some bad guy sitting in a car across the street. Because ZPA operates at the application layer, company data and other resources are invisible.

VPNs have been problematic for years, and frustrate users to no end. Businesses use them because there was no other way of enabling workers to connect when off the company premises. Zscaler has built ZPA from the ground up to connect workers to resources in a cloud- first world. ZPA is the first remote access technology I've seen that could finally put an end to legacy VPNs. ZPA is very complimentary to SD-WAN in that instead of software defining the company network it's applying the "SD" principals to access.

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