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A Quick And Easy Win Along The Path To Zero Trust: Workspace ONE's Certificate Authentication For Windows 10 And macOS

I was recently introduced to an elegant solution for enabling certificate authentication on Windows 10 and macOS devices through VMware'...

Wednesday, May 3, 2023

VMware Horizon's Uncanny Alignment With NIST Zero Trust Guidance

The foundational components for Zero Trust architectures such as MFA, ICAM and endpoint security are solutions widely deployed today.  While most organizations already have these building blocks in place achieving Zero Trust objectives with their aggregate capabilities requires a level of orchestration and synchronicity that is far less common.  In that regard, the integration and orchestration of a broad set of security components through a single platform, the Anywhere Workspace, is something VMware has been perfecting for over a decade now.  To modernize legacy windows experiences Horizon is combined with Access, UEM, and Intelligence to create a superb remote access solution uncannily aligned with NIST Zero Trust guidance.  Such a deployment meets the immediate need to optimize support for a hybrid workforce while establishing a beachhead for further Zero Trust adoption.

This post maps out Anywhere Workspace Zero Trust capabilities to guidance provided by NIST and it's subsequent work with the National Cybersecurity Center Of Excellence (NCCoE).   The intent is to elevate a discussion about Horizon and Zero Trust by referencing a source respected and followed across the public and private sector.  With federal agencies like CISA, DoD and the NSA paying deference to NIST guidance, along with it's reference by executive order 14028, treating NIST as authoritative on the topic of Zero Trust is hardly controversial and can help ground a discussion. Accordingly, this post provides a primer on NIST guidance with a focus on the notional Zero Trust architecture first introduced in (SP) 800-207, then practically demonstrated in Implementing A Zero Trust Architecture.  It then compares logical components of this conceptual model to a Horizon architecture leveraging the full breadth of Anywhere Workspace Zero Trust capabilities.  This should be of interest to anyone looking to enhance windows desktops or applications with Zero Trust security, and, if nothing else, will enable Horizon admins to articulate advancements toward Zero Trust already achieved with their deployments.

A Primer On NIST Zero Trust Guidance 

Most descriptions of Zero Trust start by declaring a need to shift from perimeter based network security to a model where hostile actors are always presumed present and within reach.  Accordingly, instead of protecting networks the focus is on controlling access to the critical resources themselves through policy based controls that continually evaluate users and their requests. As the abstract for NIST (SP) 800-207 states, “Zero trust (ZT) is the term for an evolving set of cybersecurity paradigms that move defenses from static, network-based perimeters to focus on users, assets, and resources.”  While this article focusses on guidelines put forth by NIST and NCCoE, I'd like to call out the folksier description of Zero Trust laid out by MobileJon.  For most organizations Zero Trust adoption entails a recognition that firewalls and kerberos based security provided by Active Directory no longer cut the mustard given what we know about today's threats.

Mobile Jon's Guide To Zero Trust Security

To replace perimeter based network security (SP) 800-207 introduces a notional architecture detailing logical components required to achieved Zero Trust objectives.  In the more recent NIST/NCCoE publication,  Implementing A Zero Trust Architecture, example deployments illustrate how commercially available solutions are used to achieve these ZTA objectives.  This series of guides, "demonstrate several example ZTA solutions—applied to a conventional, general-purpose enterprise IT infrastructure—that are designed and deployed according to the concepts and tenets documented in NIST Special Publication (SP) 800-207, Zero Trust Architecture." The core functionality driving these ZTA demonstrations is illustrated below: 

Zero Trust Architecture, NIST 802-207
At the top of this model there's the brains of the entire operation, the Policy Decision Point (PDP), made up of a Policy Engine (PE)  and Policy Administrator (PA).  The Policy Engine makes the determination of whether or not a subject is granted access to a given resource.  It works in tandem with a Policy Administrator responsible for executing it's decisions.  To this end the PA helps establish the communication path between subject and resource, going on to, "generate any session-specific authentication and authentication token or credential used by a client to access an enterprise resource."  Finally, there's the Policy Enforcement Point (PEP) working in conjunction with the Policy Administrator to allow or deny connections between the subject and resource.  While there's certainly more details, this is the high level model proposed by NIST for enabling Zero Trust security. 

To make informed decisions about access requests the Policy Engine processes input from various sources, what are referred to as Policy Information Points (PIP). Data from these sources is ingested into a trust algorithm that determines whether a specific request to a resource should be allowed.  Examples of PIPs include endpoint antivirus, endpoint management and security analytics solutions.  PIPs contribute to a more comprehensive, 360-degree, contextual model for continually assessing the trust worthiness of a subject.  We're not just talking about defense in depth, but rather the coordination and orchestration of various security solutions into a comprehensive model.   

Implementing A Zero Trust Architecture (Fact Sheet)
While (SP) 802-207 establishes a high level framework for Zero Trust, Implementing A Zero Trust Architecture goes into the nitty gritty of how these PIPs are pieced together with PAs, PEs and PEPs to deliver Zero Trust objectives.  Currently there's 5 sample architectures total, 3 of which are referred to as crawl phase architectures, E1B1, E2B1 and E3B1.  These first 3 builds focus on enhanced identity governance (EIG), what's viewed as a, "foundational component of ZTA."   Then, there's 2 more run phase architectures, E1B2 and E3B2,  that build upon the crawl phase.  Eventually the plan is to introduce additional advanced architectures with capabilities like micro-segmentation. "After completing the EIG crawl phase builds, we enhanced these implementations by adding specialized PE and PA components, device discovery, and cloud-based resources in the EIG run phase. In future phases, we plan to introduce capabilities such as software-defined perimeter and micro-segmentation."  Here's a graphical representation of crawl phase architecture E1B1, featuring Okta and Ivanti:

Implementing A Zero Trust Architecture, Volume B: Approach, Architecture and Security Characteristics

Again, while there's only 5 example architectures today the publication is a work in progress and there's additional examples planned for the future.  If I had the option I'd bet large sums of money that VMware products will eventually find their way into future architectures.  More conspicuous than the absence of VMware products in the current publication are the listed contributions of VMware employees in 1800-35B.  One of these five is Peter Bjork, a very high profile evangelist of VMware's Zero Trust capabilities.  While something more exhaustive and definitive might come out in an update to the publication, as a blogger and long time fan of VMware EUC I'm going to take a swag at mapping Horizon and Workspace ONE components to the notional ZTA architecture put forth by NIST.  

Mapping VMware EUC Components To A Notional ZTA 

To those familiar with VMware's EUC stack the notional ZTA put forth by NIST can come across  like a fun adaptation or clever spin on architectures put out by VMware for about a decade.   Personally, reading NIST documentation on ZTA felt like deja-vu. (all over again)  With it's identity capabilities, federation options and conditional access policies, Workspace ONE Access clearly fits the bill as a policy decision point (PDP), acting both as a policy engine (PE) and policy administrator (PA).  These identity based policies for controlling access to resources are further enhanced by solutions like WS1 UEM, WS1 Inteligence and Carbon Black.  While these provide relevant security capabilities in their own right, as sources of data providing context for access policies they're clearly acting as policy information points (PIP).  Finally, sitting between endpoint devices and virtual desktops on the data plane is Unified Access Gateway acting as a policy enforcement point (PEP). 

For over a decade WS1 Access has offered admins a way to wrap modern authentication around Horizon. It's policy engine is driven by conditional access policies that enforce an adaptable set of authentication requirements based on user context.  Some of these auth methods are built-in, some arise from a combination of Access and UEM, and others are available through 3rd party solutions via RADIUS or SAML based integrations.   While Access supports several federation standards, SAML 2.0 is definitely the star of the show, key to it's policy administration for solutions like Horizon.  Once a subject has met the requirements of these conditional access policies they're issued a SAML assertion granting access to the Horizon environment.  

The ability to drive adaptable authentication requirements through a policy engine has always been a major selling point for WS1 Access.  It's conditional access policies for each application are initially defined based on a user's AD membership, general device type, and IP range a request comes from.  This contextual insight is extended to device posture through a simple integration with WS1 UEM that incorporates device compliance status into conditional access polices.  Historically referred to as, "conditional access based on device compliance," this functionality is achieved through a combination of certificate auth and UEM's device compliance policies.  It's an option VMware has offered for about a decade now, functionality foundational to Zero Trust that's mandated by pretty much all sources on ZTA.  For example, in BeyondCorp A New Approach to Enterprise Security, a similar approach to incorporating device context is called out, with unique certificates on managed devices used as a conduit to device information. "While the certificate uniquely identifies the device, it does not single-handedly grant access privileges. Instead, it is used as a key to a set of information regarding the device." 

Access can also ingest data from Workspace ONE Intelligence regarding device and login risk, further extending the contextual insight of it's policy engine.  Both solutions represents the results of analytics run against data collected into the Intelligence data lake from Access or UEM.  Device Risk Score is driven by factors like OS patching, anomalous configuration and detected threats on a device.  Login Risk Score, "uses machine learning models to analyze past user login patterns and determine if a login attempt is anomalous." Collectively, these risks scores represent additional policy information points to further calibrate our conditional access policies by. 

Finally, there's my favorite bouncer Unified Access Gateway (UAG). Like any good bouncer it's lean on brains but intimidatingly hardened and experienced. Working in coordination with Access and Horizon Connection Server it guarantees all proxied Horizon display protocol traffic is on behalf of subjects vetted by conditional access policies.  In this capacity it acts as a policy enforcement point (PEP) for remote Horizon Connections.  Below is an illustration of how it facilitates SAML based authentication between Access and an internal Horizon environment prior to proxying display protocol traffic to a virtual desktop or RDS host. 

Setting Up Resources In VMware Workspace ONE Access

The specific model above has been alive and well for over 6 years now, having replaced a legacy Security Server based model that itself was about 5 years old.  Again, an example of Zero Trust functionality Horizon customers have had in place for about a decade. 

By encapsulating the windows experience into an portable and secure service Horizon provides a catch all solution for extending Zero Trust capabilities to legacy windows apps.  Any windows desktop experience or windows app delivered through Horizon can be wrapped in modern auth that's driven by a contextual policy engine.  This is no small feat.  We're talking legacy applications that rarely support modern auth butting heads with the Zero Trust requirement for extended identity governance.   Horizon bridges this gap to meet a fundamental requirement for ZTA.   In addition, there's many features of the stand alone Horizon solution, such as Instant Clones, that clearly advance the pursuit of Zero Trust.  Non-peristent Horizon models isolate an endpoint device from windows workloads and introduce critical containment that reduces the blast radius of any potential compromise in terms of both space and time.  The inherent security awesomeness of Horizon itself and it's contribution to Zero Trust outcomes is something I will detail in a future post. 

A Clear Path Forward For Existing Horizon Customers

Existing Horizon customers can progress towards Zero Trust adoption by making incremental improvements to their remote access experience for windows workloads.  This fulfills the immediate and practical need to support a hybrid workforce while developing capabilities for Zero Trust adoption across the board.   Customers who own Horizon Universal licensing already have the key ingredients for getting started on this journey, Horizon, UAG and WS1 Access.  These solutions meet core ZTA requirements and can later be augmented with UEM, Intelligence and Carbon Black.  This process of wrapping Zero Trust security around your windows experience is easily adapted to secure SaaS solutions like Office, Salesforce, ServiceNow, Workday or Google Workspace.  

With this framework in place you can increase SaaS adoption while expanding your Horizon deployment and shrinking the trusted network.  Further, the path forward includes incremental wins along the way that our tangible and hold value in and of themselves, allowing you to eat this elephant one bite at a time.  No one complains about having a unified catalog and providing SSO only makes friends.  MFA is something we all know is necessary and extending it's reach while minimizing disruption amounts to rolling up your sleeves and taking care of business.  Right sizing your security based on context is just good manners.  Mandating device enrollment for sensitive services is hardly controversial.   These steps represent small but very tangible wins as you progress along your Zero Trust journey.  Eventually, in a perfect world you'd have a combination of Horizon, Access, UEM, Intelligence, Carbon Black and NSX protecting workloads from endpoints to the data center.   

Some Excellent VMware Collateral On Zero Trust Adoption 

VMware provides some very impressive guidance on Zero Trust, particularly in Tech Zone.  In respect to NIST SP 800-207, EO 14028, and their impact on the federal space there's a great article by Andrew Osborn called, Incorporating VMware Zero-Trust For the Presidential Executive Order. It offers a summary of cybersecurity mandates and models created to guide federal agencies in their adoption of Zero Trust.   These include CISA's Cloud Security Technical Reference Model and Zero Trust Maturity Model.  At the end of the article Andrew states, "VMware will be augmenting our solution alignment and future whitepapers to incorporate the new CISA foundational pillars."  

Zero Trust Maturity Model 2.0

True to this promise is one of my favorite articles on Zero Trust and Horizon,  Zero Trust Secure Access to Traditional Applications with VMware.  It provides a very thorough and exhaustive account of how different capabilities across the Anywhere Workspace stack can contribute to a Zero Trust architecture for legacy windows applications.  It organizes these capabilities according to 5 pillars of trust.  They might look familiar to you.

Along the same vein there's an article on the use of VMware Tunnel for access to on-premises web applications called, Zero Trust Secure Access to On-Premises Web Applications with VMware.  Similar to the Horizon focussed article it provides a detailed and exhaustive account of the Anywhere Workspace capabilities that enable Zero Trust security for on-premises web apps.  Finally, anything put out by Peter Bjork is likely to further your understanding of Zero Trust capabilities offered by VMware. With extended identity governance at the core of Zero Trust, his expertise in WS1 Access is highly relevant.  


To quote chief justice Earl Warren, “Everything I did in my life that was worthwhile, I caught hell for.” Implementing Zero Trust isn't going to be fun, will involve a lot of work and invariably is going to frustrate some people.  It's an interdisciplinary undertaking transcending traditional IT silos filled with hyper-focused specialist who don't get paid to think or care about the big picture.  Success will require grit and confidence while striking a balance between the status quo and need to transform security.  In a situation like this a mature platform integrating a broad set of capabilities really shines.  With the Anywhere Workspace we gain a guaranteed level of interoperability amongst separate components needed to realize a Zero Trust architecture.  Instead of sweating details about interoperation why not pass the work off to a single vendor with a solution that has aligned with NIST guidance for over a decade, long before (SP) 800-207 was even published?  It's a path forward most existing Horizon customers can pursue with components already owned and in place.   

Wednesday, November 30, 2022

The Innovation And Current Limitations Of VMware's Universal Broker For Horizon

VMware's Universal Broker allows Horizon users access to multiple Pods through a single URL, routing sessions based on resource availability, entitlements and shortest network paths.  Traditionally, multi-site Horizon deployments require a combination of Cloud Pod Architecture (CPA) and 3rd party global load balancers to provide fluid failover and fall back.  Universal Broker, part of the Horizon Control Plane, replaces these requirements with a purpose built SaaS based offering.  The solution leverages the control plane's privileged insight into Horizon environments to deliver more efficient and error free placement of Horizon sessions across Pods.  This addresses shortcomings of traditional CPA/GSLB deployments while laying the ground work for integrating Horizon deployments across various cloud vendors.  

All that said, there are certainly caveats and limitations to the solution.  In fact, you might say there's a conga line of caveats and limitations.  However, while the technology is currently going through an awkward teenage phase of sorts, overall its a clever and compelling solution with a promising trajectory. It's not just a one for one replacement for CPA and 3rd party GSLB.  Universal Broker is an elegant innovation, a purpose built SaaS based solution for Horizon that parlays environmental information from the control plane into more efficient and error free placement of sessions.  Key to its efficacy is an innovative bifurcation of the Horizon protocol, with the primary and secondary protocols following separate network paths.  This shift helps avoid the need for east-west replication traffic between Horizon Pods, as is the case with CPA.   Further it solves for a particularly acute affliction with east-west interpod traffic called Horizon protocol hair-pinning, a potential pitfall for the traditional combination of CPA and 3rd party GSLB.   Overall, Universal Broker simplifies and improves on-premises multi-site deployments while enabling the effective adoption of Horizon 8 cloud based workloads.  It's also integral to the new next-gen Horizon Control Plane currently supported for Horizon on Azure. This post will provide a brief overview of Universal Broker, the hair-pinning challenge it addresses, its setup for Horizon 8 environments and some current limitations.  

The Innovation Of Universal Broker For Horizon

Along with making it easier to deploy and support the cloudiness of Universal Broker is key to more efficient routing and placement of Horizon sessions across Pods.  As part the Horizon Control Plane it has privileged information about home sites, resource availability, and established sessions, affording its global load balancing functionality a greater degree of integration with Horizon.  Traditionally 3rd party GSLBs and CPA at best can be well coordinated with Horizon, but nothing near the synchronization achieved through Universal Broker.  A further departure from the traditional model is how Universal Broker bifurcates Horizon protocol traffic into two separate network paths.   The primary Horizon protocol traffic, which handles authentication, travels between the client endpoint device and Universal Broker in the cloud.  The secondary Horizon protocol traffic, the display protocol, traverses a second path between the client and actual Horizon environment.  

For context, below is a representation of the flow of Horizon protocol traffic for a normal remote Horizon connection.  Typically the primary protocol traffic is over TCP port 443 from the endpoint client through the Unified Access Gateway (UAG) appliance onto the Connection server.  If this authentication is successful the Horizon secondary protocol kicks into gear, establishing a display protocol connection between the endpoint client and the virtual desktop.   Under normal circumstances, using the Blast display protocol, this would consist of 8443 UDP based traffic to the UAG appliance and 22443 UDP traffic from the UAG appliance to the virtual desktop.  

With Universal Broker the Horizon protocol is bifurcated, traveling across two separate network paths.  The primary Horizon protocol consists of a connection directly against Universal Broker for authentication over TCP 443.   After successful authentication the secondary Horizon protocol traverses a connection between the endpoint device to the Horizon Pod itself.  Again, under normal circumstances for Blast it would be UDP 8443 to the UAG appliance and UDP 22443 from the UAG appliance to the virtual desktop.   Overall, we're talking about two very separate network paths.  One from the endpoint device to the Universal Broker service in the Control Plane and a second path from the endpoint device to the Horizon environment itself.  

So, when Universal Broker is in the mix the entire primary Horizon protocol connection is shifted and offloaded to the cloud.  Though, relatively speaking the vast majority of Horizon protocol traffic is secondary protocol traffic, this shift of the primary protocol traffic is still significant, simplifying support of initial connectivity.   If a user fails to authenticate to their Horizon environment through Universal Broker you don't need to investigate site specific challenges providing external world access to Horizon services.  No load balancers to troubleshoot, no questions about client network connectivity to your on-premises environment and, if you leverage a subdomain of vmwarehorizon.com, no concerns about DNS records or expired certificates.  All these typical primary protocol concerns are offloaded to Universal Broker.  If the user is failing to see their entitlements most likely they're fat fingering their password or just failing to have access to the internet.  By shifting the primary protocol exchange to the cloud a lot of the nittier grittier troubleshooting for remote connectivity is circumvented or at least simplified.  

The Horizon secondary protocol, the display protocol, is most relevant and impactful when it comes to user experience.  Fortunately, the network path traversed by this protocol is established post authentication based on Universal Broker's assessment.  An optimum Horizon Pod is judiciously selected based on, "insider information," regarding the status and configuration of the Horizon environment and entitlements.  This leads to global load balancing that's better informed by the Horizon solution, providing a tighter integration than normally achievable.   It's easy to appreciate this improvement when you consider an esoteric pitfall of the older traditional GSLB/CPA model: Horizon protocol traffic hair-pinning.  

Horizon Protocol Traffic Hair-Pinning - Ouch!

For over a decade now VMware has offered a fully redundant Horizon architecture for customers who need a bullet proof, highly available Horizon deployment. It used to be referred to as, "AlwaysOn Point Of Care," in homage to the healthcare customers that were particularly fond of the solution. Nowadays, it's consider just plain redundancy, or a Horizon Multi-Site architecture. Prior to Universal Broker, an absolute requirement for this architecture was some combination of a 3rd party global load balancer and Cloud Pod Architecture (CPA).  The GSLB solution provides a single name space for multiple sites, while CPA replicates entitlements, resource status and current session information between the separate Horizon Pods, providing minimal integration between otherwise fully redundant and independent Horizon environments.  This ensures fluid failover and fall back in response to disruptions and outages, while also ensuring folks get properly routed according to home site preferences or pre-existing sessions.  

This model has been good enough to make it throughout the last decade but has a couple caveats less than ideal for traditional on-premises deployments and complete deal breakers for certain types of cloud based deployments. First off, it's predicated on network connectivity and east-west traffic between Horizon Pods, a requirement for replicating entitlements, resource availability and session status across separate environments.  It's a potential challenge when you consider these Pods could be very far away from each other or on different clouds.  

While CPA traffic isn't too extensive and is typically manageable,  the need for east-west traffic between sites can really spike when remote connections through UAG appliances are in the mix and global load balancing isn't executed flawlessly.  This ties back to UAG and how it handles the Horizon protocol.  Traditionally you must have both the primary and secondary Horizon protocol traffic go through the same UAG appliance.   In fact, outside of Universal Broker deployments, it's an absolute requirement.  UAG's prime directive is to ensure all display protocol traffic passed is on behalf of a strongly authenticated user.  To achieve this it only passes secondary protocol traffic for sessions its handled primary protocol traffic for.  There's no way for UAG to communicate authenticity of a Horizon user to other UAGs.   So, under normal circumstances, the same UAG that handles primary protocol traffic must handle the secondary protocol traffic or the session will otherwise break.  This is by design.  Now, this requirement for UAG can have some rough consequences in the context of a traditional Horizon multi-site architecture.  If the 3rd party global load balancer doesn't do a flawless job getting folks routed to the proper Pod, there's potential for an inefficiency referred to as Horizon protocol traffic hair-pinning.  

For example, say an organization has two PODs, one in New York and one in Los Angeles.  Then a jet setting banker working for that organization connects to his virtual desktop from a Manhattan penthouse.  Accordingly, the GSLB routes him to the Horizon POD in New York.   He disconnects from his virtual desktop, kisses his wife and kids good bye, then jumps on a private jet with his mistress for a weekend getaway to the Grand Teton National park in Wyoming.   When he reaches the hotel room in Wyoming he remembers, "oh shoot I forgot a quick thing for work," then connects to his Horizon environment.  The global load balancer sees he's in Wyoming and routes him to the closer California Pod.   He hits the Horizon Connection server in California and through CPA the Connection Server is aware of the banker's currently open session in New York.  It routes him back to that currently open session.  Great, except, because he's initially connected the California Pod through a UAG appliance in California, he has to continue using that UAG appliance.  So his traffic has to go from Wyoming to California, then back across the US from the UAG appliance in California to the Horizon Pod in New York.  An extreme but perfect example of Horizon protocol hair-pinning.   Not only could it make for a lousy user experience, but it could lead to an excessive amount of east-west traffic beyond what's been planed for.  

This example is extreme, but by no means outside the world of possibilities.  There's certainly ways you could fine tune the coordination of your 3rd party global load balancer and Horizon environments to mitigate this challenge.  (For instance I've heard F5 has an APM module that can more accurately route a user to a Pod where they already have an established session.)  However, I don't think creating a GSLB/CPA solution that's bullet proof is a cake walk and that's why this challenge is called out in the Tech Zone article, Providing Disaster Recovery for VMware Horizon.   If you don't get things just right the impact could be fairly brutal on your user experience and networks, possibly in the middle of an outage, when hair-pinning challenges are the last thing you need.  Potential for particularly acute challenges arise when considering cloud hosted desktops.  Both the AWS and GCVE guides warn against this potential hair-pinning.  In these scenarios, hair-pinning has the potential to saturate capacity on NSX gateways and kill session density.   Further, it could lead to some expensive and senseless traffic flow between on-premises and cloud environments.  Accordingly, it's recommended to leverage Universal Broker instead of CPA for these Horizon 8 based cloud deployments. 

Despite working with Unified Access Gateway for over half a decade now I was completely blind sided by this esoteric gotcha.  It took awhile for this challenge to sync in, but when it did, oh boy, did it!   Fortunately, we can completely side step this potential pitfall by adopting Universal Broker.  With Universal Broker no traffic hits a UAG appliance until after there's been a successful authentication against the cloud and an ideal path has been determined.   So, with the adoption of Universal Broker we avoid this esoteric, but real, pitfall with on-premises Horizon environments while laying the ground work for successful multi-site adoption with cloud hosted virtual desktops.  Speaking of cloud hosted desktops lets talk about Universal Broker and it's role in the next-gen Horizon Control Plane for Horizon on Azure. 

Universal Broker And The next-gen Horizon Control Plane (Titan)

For the next-gen Horizon Control Plane, currently limited to Horizon on Azure, Universal Broker is an essential built-in component.  It plays a critical role in the transformation to a Horizon thin edge, helping eliminate the need to deploy Horizon Connection servers within Azure.  Instead, there's a light weight deployment of a thin Horizon Edge on top of native Azure, consisting of only UAG appliances and Horizon Edge Gateways.  The rest of the traditional infrastructure used to manage the Horizon environment is shifted to the next-gen Horizon Control Plane.  This reduces consumption of Azure capacity while simplifying the deployment and maintenance of Horizon.   

Again, with this next-gen architecture Universal Broker is an absolute requirement, an integral part of this new model. So much so, it doesn't even get specifically called out in the next-gen reference architecture or official documentation.  It's functionality requires no extra configuration and is assumed available as entitlements are created.  While this new, stealthier, iteration of Universal Broker is certainly easier to deploy it's only available with the next-gen Horizon Control Plane, so its limited to Horizon on Azure for now.   For those leveraging Horizon 8 deployments on-premises or on top of various SDDC public clouds - AVS, GCVE, AWS  - v1 of Universal Broker is still relevant. At Explore Europe 2022 VMware announced intent on extending next-gen architecture to Horizon 8, but it's limited in scope as of today and there's no committed time line for extending it's newer iteration of Universal Broker to Horizon 8.  In the mean time there's the traditional Universal Broker deployment that's been available for sometime now and, while it's not as easy to deploy as v2, it's not rocket science.  

Setting Up Universal Broker With My On-premises Lab 

Since the setup of Universal Broker for Horizon 8 is well documented I'm just going to provide a high level overview, call out some specific challenges, and include links to relevant documentation for those who want to get into the nitty gritty.   The official documentation calls out four major steps for setting up Universal Broker for Horizon 8 environments.  Assuming you already have a current version of Horizon Cloud Connector up and running, the next steps are:

  1. Installing the Universal Broker Plugin on all Connection Servers 
  2. Configuring your UAG appliances with the required JWT settings 
  3. Enabling Universal Broker in your Horizon Universal Console 
  4. Configuring multi-cloud entitlements within the Universal Console 

Again, these steps are well documented in both the official documentation for Horizon Cloud Control Plane and a really nifty Tech Zone article called, "Configuring Universal Broker For Horizon."   Below is an excellent graphical representation of the architecture.  

While in hindsight the configuration of UAG was relatively straightforward I personally struggled with it. The relevant settings are configurable through the web interface for the UAG appliance by navigating to  advanced settings and clicking the gear box for JWT.  All the settings to input are in regard to the supported Horizon Pod itself and are specially detailed here in the documentation.  First off there's the cluster name of the Horizon Pod.  Unless you've bee supporting CPA, you've probably never been aware of this property.  Its case sensitive so use caution.  (I had challenges with this portion of the setup because CPA had been enabled for my Pod in the past, though it currently wasn't in use.  That had the affect of changing the name of the cluster that was displayed versus what was needed for the UAG setting.)  

Another setting I initially struggled with was the Dynamic Public Key URL.  This essentially amounts to appending "/broker/publicKey/protocolredirection" to the internal FQDN of your Horizon Pod.  (I would think it's always going to be the same FQDN used for your, "Connection Server URL," under Horizon Edge settings.)   Likewise, the, "Public key URL thumbprints," is the certificate thumbprint used by the FQDN leveraged for the Dynamic Public Key URL. (Again, probably the same as your Connection Server URL Thumbprint under Horizon Edge settings.).  So, overall, the values are fairly similar to values you you're using already for your UAG's Horizon settings, but they have weird fancy names that can throw you off.   For context, here's the settings I typically use for my Horizon Edge settings:

And here's the JWT settings for Universal Broker: 

In hindsight it all makes sense enough but in the context of setting up a new solution it was a bit confusing at first.  Another gotcha I  bumped into was the need to define your desktop pools as, "Cloud Managed," when initially creating them, prior to creating your multi-cloud assignments within the Universal Console.  Fortunately, once you know to do this, the procedure is simple enough.  As you're walking through the desktop pool creation wizard check the box for, "Cloud Managed," and you're good to go.

Again, there's a great article in Tech Zone that covers the the setup of Universal Broker called, "Configuring Universal Broker For Horizon."  I'm sorry to say I didn't learn about this articles existence till I was almost completely done with the setup.  Instead, I slogged through the entire setup using the official documentation, "Administration of Your Horizon Cloud Tenant Environment and Your Fleet of Onboarded PODs."  It was doable, just not the smooth and enjoyable guidance of a well put together Tech Zone article.  

Other portions of the setup were fairly straight forward.  For instance, installing the Universal Broker Plugin was just a matter of locating the right version for my Connection Servers, accepting defaults, and going next-next-finish.  Configuring the Broker service in the Universal Console was easy and straight forward as well, particularly because I choose to go with a subdomain of vmwarehorizon.com, rather than a customer provided FQDN.  This avoids the need to generate any SSL certs or create any external DNS records, which I found to be a lovely convenience.  (Otherwise, you can go with the customer provided option, then enter in your own FQDN and provide a cert.). 

With the plug-ins installed on your Connection Servers, UAG's properly configured and Broker enabled, you're ready to start creating your multi-cloud entitlements from the Universal Console.   It's a relatively straight forward process so I'll leave that to the official documentation.  

One final thing I'd like to point out is that you can configure UAG's to support Universal Broker, without disrupting their use for traditional UAG access to Horizon environments.   So folks can continue to hit these UAG devices directly for access to traditional Horizon pools while in parallel they can support access through Universal Broker.  Further, while the local pools used for Universal Broker multi-cloud entitlements are configured from Universal Cloud, the entitlements made from the cloud trickle down to the local pools so these local pools are also accessible through direct UAG connections. 

Current Limitations Of Universal Broker 

While Universal Broker presents some interesting innovation and a compelling future there's definitely some limitations.  Most notably, Universal Broker v1 doesn't support application pools across multiple Pods.  You can deliver a single Pod based application pool but you're not going to get load balancing for application pools across multiple Pods.    So, as far v1 of Universal Broker is concerned, there's isn't parity between application pools and virtual desktop pools.  Another limitation as of today is no support for mixing Horizon 8 based Pods and Horizon Cloud based Pods. (Horizon on Azure.)  So, for example, you can't have a multi-cloud entitlement that spans across an on-premises Horizon 8 Pod and a Horizon on Azure environment.   However, you could have a multi-cloud assignment that spans across an on-premises Horizon 8 Pod and Horizon 8 Pod running on top of AWS, GCVE or AVS.   It comes down to whether your deployment use traditional Horizon 8 Connection Servers or not.   If they do then they can share multi-cloud entitlements with one another. (Assuming they're not application pools.)

There's also challenges regarding support for stronger forms of authentication.  Leveraging the built in capabilities of UAG, there's support for RADIUS and RSA.  However, there's no support for smart cards or certificate auth.  Further, there isn't support for direct SAML integrations between UAGs and 3rd party IDPs, one of the fastest growing methods for strong authentication within the DMZ through UAG.  So no support for direct integrations with IDPs like Okta, Ping or Azure.   That said, there is support for Workspace ONE Access, which in turn can be integrated with this 3rd party solutions.   So Workspace ONE Access can be configured as a trusted IDP for Universal Broker, which in turn can leverage 3rd party solutions that have been configured as trusted IDPs for WS1 Access. (Kind of like the good old days before UAG started supporting direct integrations.).  

The integration of Universal Broker with WS1 Access makes for interesting discussion because there's a lot of confusion about the ability to replace the solutions with each other.  While there's some slightly overlapping capabilities in the two products, by and large they are complementary solutions with very different competencies.   Sure, Workspace ONE Access is a way to provide users with a single URL for access to multiple Horizon PODs,  but the solution is squarely focused on identity and wrapping modern authentication around Horizon access.  It's by no means a global load balancing solution.  Conversely, while Universal Broker can support strong authentication through RADIUS and RSA,  its core competency is providing global load balancing based on shortest network path, assignments and current Horizon environment status.  So, when you focus on the core competencies of each of these solutions, what they're really good at, combing the technologies is possibility worthy of consideration.   For a great overview of this integration, check out the section, "Workspace ONE Access And Horizon Integration," with  the Tech Zone article, Platform Integration.  Below is a great diagram of the integration.  

However, there's an important caveat to be aware of.  With this WS1 Access integration, as it stands today, there isn't an option to configure unique WS1 Access policies for the multi-cloud entitlements supported by Universal Broker.  Buried in the documentation, under a section called, "Horizon Cloud - Known Limitations," it states, "access policies set in Workspace ONE Access do not apply to applications and desktops from a Horizon Cloud environment that has Universal Broker enabled." Instead, all the Universal Broker entitlements are protected by the default access policy of WS1 Access.  Depending on your deployment this may or may not be a deal breaker.   If you're using WS1 primarily for your Horizon deployment, and all your entitlements have the same access policy requirements, then having them all share the same default access policy could be feasible.  However, if you need granularity in terms of your WS1 Access policies for these multi-pod assignments, say stricter requirements for some specific pools than others, this could be a problem.   Or if you have a fairly mature WS1 Access deployment and want looser requirements for initial portal access it could be a challenge.  For more granular WS1 Access policies to use for your desktop you need to fall back to Virtual App Collections which, unfortunately, are incompatible with Universal Broker.   

The Trajectory Of Universal Broker And next-gen Horizon Control Plane

As called out earlier in this post, VMware recently announced plans to extend the next-gen Horizon Control Plane to Horizon 8 environments for better support of hybrid deployments across on-prem and Azure.   Given Universal Broker is transparent and built into the next-gen Control Plane, extending this new control plane architecture to Horizon 8 shows a lot of promise for addressing the limitations of Universal Broker v1 as of today.   Right off the bat, the next-gen Horizon Control Plane supports application pool entitlements across multiple Pods, addressing a long standing limitation.  Further, extending support to Horizon 8 certainly implies that challenges with multi-cloud entitlements across Horizon and Horizon Cloud PODs  will be addressed.  Finally, there certainly appears to be commitment to ironing out challenges combining Universal Broker functionality with Workspace ONE Access.  With this next-gen architecture, use of an IDP is no only supported, but is an absolute requirement.   As of today there's a choice between WS1 Access or Azure.  

Though there's no fixed promises made by VMware as of today, with this next-gen Horizon Control Plane and Universal Broker there's a clear trajectory towards addressing a lot of todays challenges.    


While there's work to be done and gaps to bridge I'm still incredibly excited about the Universal Broker technology and think every Horizon admin should at least be familiar with it.  In some ways it reminds me of Instant Clones circa 2016 or UAG in 2015, back when it was called, "Access Point."  Both these solutions seemed a little crackpot or science project-ish at the time.  They weren't quite ready yet, not done baking till... they just were.  Though we definitely had our reasons for being suspect or dubious upon their initial release these solutions eventually rounded the corner and established themselves as standard technologies, core to the Horizon stack.  I think the case will be the same for Universal Broker simply because it has a lot going for it.  First and foremost, it's not a solution looking for a problem, but rather a purpose built solution for addressing a Horizon specific requirement.  More notably, the way it solves this challenge from the cloud makes it both clever and easy to deploy, while lending Horizon admins a greater degree of autonomy.  Eventually, its adoption will become the path of least resistance.  I wouldn't necessarily implore admins to rip out their current working implementations of CPA\GSLBs and slam this technology in.  However, as new multi-site implementations get stood up I think the customer base will slowly migrate over to this new solution.  By the time it becomes a new standard we probably wont even call it Universal Broker anymore.  It will just be multi-cloud assignments through the Horizon Control Plane, something we take for granted.  

Wednesday, August 3, 2022

If You Can't Bring Your Virtual Desktop To The Cloud, Bring Cloud To Your Virtual Desktop

In late June of this year I had the honor of pre-recording a VMware Explore session with Todd Dayton and Cris Lau.  The session, "Can't Take Your Virtual Desktop To The Cloud? Bring Cloud To It,"  focuses on ways to enhance on-premises Horizon environments with VMware hosted services.   It stems from a recognition that shifting VDI capacity to the cloud is not quite feasible for many customers, at least not yet.   As Todd put's it, "VDI really isn’t an application workload itself. It’s a support system for Windows applications that typically can’t or wouldn’t be modernized….These Windows applications aren’t always a great cloud candidate."  So, sure, you can stuff any application in a cloud based desktop, but if it's too resource hungry, too latency sensitive, or generates too much ingress/egress traffic there could be problems.  Performance or cost savings, or both, can take a serious hit.  For this and other reasons lots of customers have decided to keep virtual desktop workloads on-premises.  However, all is not lost.  There's still plenty to gain from slathering cloud services on top of existing on-premises Horizon environments, shifting management, monitoring, and security to VMware's SaaS offerings.   

These VMware hosted services ease the burden of on-premises Horizon management while wrapping modern capabilities around traditional Windows workloads.  For day 2 operations the Horizon Control Plane, with features like the Universal Horizon Console, Help Desk Tool, and Assist for Horizon, enables effective support  from anywhere in the world.  Further, a subset of the Horizon Control Plane called the Cloud Monitoring Service (CMS) offers high level monitoring and reporting against Horizon from the cloud, capabilities recently improved upon through Workspace ONE Intelligence for Horizon.  Along with SaaS based support and monitoring there's the ability to enhance remote Horizon access with cloud based Workspace ONE and Carbon Black.   These services allow customers to wrap modern capabilities around Horizon sessions while facilitating adoption of 3rd party SaaS like Office 365, Okta, and ServiceNow.  The end result is a comprehensive remote access solution, an on-premises Horizon environment augmented with cloud based services to deliver a digital workspace for remote and hybrid workers. 

COVID-19 Brings Horizon Remote Access To The Foreground

Horizon is more relevant than ever given the spike in remote and hybrid work driven by the pandemic.  For nearly 15 years Horizon had been a relatively niche solution, adopted primarily by segments sensitive to security and regulations.  Despite this narrow vertical adoption, over the years Horizon progressively improved at remoting Windows through updates to its clients, agents and the Blast display protocol.  This finely tuned capability was an absolute godsend as customers scrambled to accommodate remote access in the early days of the pandemic.

While Citrix and Horizon are very similar solutions, a clear distinction emerges as one explores innovations for remote access.   For Citrix, remote access centers around hardware based versions of Citrix ADC, the artist formerly known as NetScaler.   You place these multipurpose network appliances in your DMZ and, as they are packed with impressive but for most customers largely extraneous features, they cost a small fortune.  In contrast, remote access for Horizon is handled by a free and flexible software based solution, a virtual appliance called Unified Access Gateway (UAG).  It's a mature bespoke technology for securing remote Horizon access with a proven track record integrating with 3rd party solutions to beef up security.  That said, it shines brightest when we combine it with the Workspace ONE suite to wrap functionality like identity and modern management around remote Horizon sessions.  This approach enhances remote access from the cloud while allowing customers to purchase germane technology a la carte. 

VMware Hosted Services Wrap Comprehensive Security And Management Around Remote Horizon Access

Over half a decade ago Workspace ONE UEM (AirWatch) was already shifting towards predominantly SaaS based adoption.  There's certainly exceptions, but generally speaking Workspace ONE UEM is a cloud first solution.   The same goes with Workspace ONE Access nowadays, as customers are entitled to a SaaS based tenant through their Horizon Universal subscriptions.  Offering a unique integration of identity and endpoint management capabilities, WS1 UEM and Access combined offer amazing enhancements to remote Horizon access like contextual authentication, endpoint management, and SSO.  This ideal model for remote and hybrid workers is further enhanced through Workspace ONE Intelligence.  Intelligence, along with providing advance reporting capabilities, enables ruthless automation against WS1 UEM environments as well as any 3rd party solutions supporting REST APIs.  Finally, Carbon Black, a VMware acquisition from 2019, provides cloud based next-gen antivirus for Windows 10 and macOS.   When these VMware hosted services are combined with Horizon you get a solution ideally suited for remote and hybrid workers, a superb remote access Horizon experience augmented with mature cloud based security and management. 

These SaaS offerings wrap remote Horizon sessions in modern capabilities like Zero Trust, beefing up security for Windows applications that historically have been less than secure.   Further, while these services are a natural fit for remote endpoints, we can also use them to manage virtual desktop images themselves.  WS1 UEM can be used to manage persistent VDI and Carbon Black is supported on both Instant Clones and Full Clones.  Likewise, WS1 Access can be used to secure SaaS adoption both inside and outside the virtual desktop. 

Harnessing 3rd Party SaaS Based Solutions For An Enhanced Horizon Experience

When it comes to enhancing Horizon from the cloud it's not just about VMware hosted services, but also 3rd party SaaS like Office 365, Okta or ServiceNow.  For over a decade WS1 Access has made access to 3rd party SaaS easy and secure for Horizon users.  Within the virtual desktop it offers incredibly convenient consumption of SAML integrated applications through the WS1 portal or directly from any supporting Windows apps.  Outside the virtual desktop security can be fully addressed by WS1 Access and the rest of the Workspace ONE suite.  As with Horizon, we can use the Workspace ONE suite to enhance and secure access to these SAML integrated solutions. 

In addition to enabling the adoption of cloud based service providers, there's the option to leverage solutions like Okta, Ping or Azure as identity providers.  By configuring these services as trusted IDPs we can leverage their authentication mechanisms for securing Horizon or any other Workspace ONE integrated application. It's a way to beef up the already impressive set of Workspace ONE security capabilities, another way of bringing cloud to the desktop. 

Finally, there are two very interesting ways in which Workspace ONE Intelligence facilitates cloud adoption.  First, through the Trust Network it can ingest threat events not only from Carbon Black, but other cloud based members of the Trust Network like Lookout.  Second, events collected in the Intelligence data lake can trigger actions through automation connectors.  Out of the box there's built-in connectors for WS1 UEM, Slack and ServiceNow, however there's an option to create custom connectors for any solution that offers a REST API. 

These automation connectors represent an amazing opportunity to fine tune enhancement and support of Horizon environments from 3rd party cloud services.  Horizon admins are usually grizzled veterans when it comes to scripting within the desktops.   With Intelligence they can now turn their attention to scripting against SaaS, automating REST API calls to 3rd party cloud solutions that are becoming increasingly relevant.

The Horizon Control Plane Services 

Horizon Control Plane Services enable day 2 support for on-premises Horizon environments from the cloud.  Its Horizon Universal Console provides Horizon administration enterprise wide through a single web based URL while also providing global access to the Help Desk tool.  So a support team, wherever they are in the world, without the need for direct network access to Horizon environments, can look up real time session details for any Horizon user.  They'll also have the ability to troubleshoot through actions like killing processes or restarting VMs.  If necessary there's even an option to remote into a virtual desktop using Workspace ONE Assist for Horizon.  Finally, for more high level support and monitoring, "the big picture," there's the Cloud Monitoring Service (CMS).  CMS provides health, capacity, and usage metrics for any cloud connected Horizon environment.  (For example, if a certificate expires on a Horizon Connection server, this challenge will trickle up to the Horizon Universal Console through CMS.)  The Universal Console, the Help Desk tool, Assist for Horizon and CMS all connect to on-premises environments through the Horizon Cloud Connector and clone Worker Node(s) that provide redundancy.   

While CMS provides high level insight Workspace ONE Intelligence for Horizon provides additional detail, granularity and customization in terms of monitoring and tracking the health of your on-premises Horizon environments.  This provides more in-depth support for day 2 operations while laying the ground work for future Workspace ONE integration with Horizon.

Workspace ONE Intelligence For Horizon 

Workspace ONE Intelligence For Horizon was first announced during VMworld 2021 and as of July 28th, 2022 is generally available.   This rounds out the overall strategy of porting information from all VMware EUC components into Intelligence.  For someone that specializes in both Horizon and Workspace ONE this is welcome news.  Intelligence has been offering advanced reporting and automation for WS1 UEM for years now and it's great to see VMware extend this functionality to Horizon.  

This first iteration provides built-in dashboards, custom reports, and custom dashboards, expanding beyond the canned reporting capabilities of CMS.  We're talking boat loads of raw and relevant data regarding the health and performance of Horizon. Just to give you a taste of how vast this dataset is here are screenshots from Intelligence custom reports detailing visible attributes from Horizon PODs, Pools and VMs:

Even more impressive and overwhelming are the available, "Session Snapshot," attributes:

So yeah, there's a lot to work with here. While this info is relevant for Horizon health and performance monitoring across the board, it certainly rounds out the already impressive model of supporting remote Horizon access with cloud based services. When troubleshooting performance challenges with remote access it can provide critical network insight like display protocol packet loss and round trip latency, along with detailed information of virtual desktop resource usage.  You also get invaluable context regarding general POD health and performance.  Finally, you get the ability to slice and dice through this information with WS1 Intelligence customizable dashboards and widgets, allowing you easily zero in on and visualize relevant data.

The fact we get this info enterprise wide from a cloud based service is quite compelling and affords Horizon customers an opportunity to really up their game in terms of monitoring Horizon performance.  Further, as a cloud based service that leverages Horizon Cloud Connectors many customers already have in place, it's very accessible and easy to stand up.  (It took me less than 15 minutes to get it working for my lab.)  Finally, it comes standard with most of the new Horizon entitlements at no additional cost, so the price is right.  

A VMware Explore Session On Extending Cloud To The Virtual Desktop

Though not everyone is ready to move their VDI workloads to the cloud all existing Horizon customers stand to benefit from the adoption of VMware hosted services.  These services, already available today, can be layered on top of existing Horizon environments non-disruptively and easily.  These are the main takeaways of the explore session,  "Can't Take Your Virtual Desktop To The Cloud? Bring Cloud To It."  It begins with an amazing introduction from Todd Dayton.  He elaborates on the benefits of cloud adoption, challenges with Windows workload migrations to the cloud, and the ideal compromise of shifting Horizon management to the cloud.  Then Cris Lau provides an impressive demo of the Horizon Universal Console, Help Desk tool, Assist for Horizon and Intelligence for Horizon.  Finally, I wrap things up reviewing ways we can enhance remote Horizon access with cloud based Workspace ONE and Carbon Black. 

Also, one final anecdote.  Todd pointed out that even if you're confident your virtual desktop workloads will eventually get migrated to the cloud there's absolutely nothing lost if you start off with these cloud based enhancements to your on-premises environment today.  It's not like you'd be burning any bridges or painting yourself in a corner.  In fact, arguably you'd be stacking the deck in your favor for a successful workload migration by already having cloud based management services configured, adopted and in place.  So there's really nothing to loose except the burden of managing on-premises resources.