Kilroy Realty, Dartmouth, and McKesson Overhaul OT Networks for Resiliency, Tech-enablement

Modern operational technology (OT) teams face a stark reality: as buildings bristle with new IoT devices and smart systems, the once-isolated and overlooked building control networks are now mission-critical and exposed to new risks. Seasoned OT professionals have learned the hard way that an unreliable network can grind operations to a halt, whether it’s an HVAC system offline because of noisy BACnet devices or a security system vulnerable to cyber threats. 

The solution emerging across leading organizations is a convergence of IT and OT skills and infrastructure. At NexusCon 2024, we learned how Kilroy Realty, Dartmouth College, and McKesson are breaking down traditional silos and reinventing their building networks to meet real-world operational challenges.

OT managers will recognize the skepticism that often greets new IT initiatives in facilities (“if it ain’t broke…”), but these examples cut through theory with practical, hard-won lessons. From wrangling misbehaving BACnet devices on a college campus to securing distribution centers that literally drive a Fortune 500 revenue stream, the message is clear: 

The network is now as fundamental to facility operations as the thermostat. 

IT Meets OT in Real-World Examples

Historically, building systems lived on their own islands, far from the purview of corporate IT. In many facilities, the “network” for the building automation system (BAS) was put together by whoever managed the controls—often just “a guy who went to Best Buy and bought a router and an unmanaged switch”. 

That Wild West approach now spells trouble. HVAC Professionals and access control professionals are experts at just that… HVAC and access control. But more data and more connectivity require networking skills to become just as important for these roles. The proliferation of internet-connected devices, from IP security cameras to smart elevators, has opened up vulnerabilities and performance issues that traditional facilities teams aren’t equipped to manage.

All three organizations—Kilroy, Dartmouth, and McKesson—realized that bridging the gap between IT and OT was essential to the performance and security of their buildings. Dartmouth College’s facilities team likewise partnered with campus IT networking experts and effectively became a customer of the central IT network services to run the campus building systems. Kilroy Realty, a real estate investment trust with over 100 buildings, tackled this by embedding an OT group within its corporate IT department to provide “technology leadership” to facilities teams. At McKesson, a Fortune 10 healthcare distributor, the real estate technology team had to, as Drew DePriest put it, “cozy up to the people that know how to [manage switches]” on the corporate network, integrating OT devices into an environment with enterprise-grade cybersecurity controls.

In each organization, OT staff had deep knowledge of building systems but limited networking expertise, while IT staff knew networking but had little exposure to HVAC, lighting, or industrial controls. In all three cases, bringing these IT and OT teams closer together created a unified approach to treating building operation networks with the same process-oriented methods that IT networks use. This requires a cultural shift: OT engineers learning about VLANs and IP addresses, and IT analysts gaining appreciation for HVAC and building schedules. The result is very tangible technical improvements.

Dartmouth College: Taming BACnet and Unmanaged Networks

At Dartmouth College, a series of renovation projects exposed how fragile a legacy building network could be in the face of modern demands. “We really had a challenge with design coordination…getting the details right specific to BACnet,” said Doug Plumley, a software architect at Dartmouth, referring to a recent overhaul of Dartmouth Hall. The college was transitioning from old serial BACnet networks to BACnet/IP, and the scale of that change created unexpected chaos. 

Simple missteps like an Ethernet loop or an unmanaged switch in the BAS network didn’t just affect one building—in some cases, it took down multiple buildings on campus. As Plumley put it, BACnet is a “great protocol… but essentially an application in and of itself, and you need to manage it that way”. In other words, you can’t treat the BAS network as a casual afterthought anymore.

One root cause was the chatty nature of BACnet/IP when poorly configured. A standard BACnet “Who-Is” broadcast works fine in a building with 100 devices, but when that BACnet style of device discovery is happening across a campus with 5,000 devices, it can become chaos. In Dartmouth’s case, the BAS networks had traditionally been daisy-chained with minimal IT oversight, sometimes only one IP interface per building, but as new projects added dozens more IP devices, the old approach crumbled. Broadcast storms and IP address conflicts started popping up, and troubleshooting could drag on for weeks or months as OT staff tried to identify offending devices without proper network tools.

Moreover, Dartmouth has two different OEM controls systems and two separate OEM service contractors servicing them. Coordinating a unified BACnet structure across both vendors doubled the complexity of creating a unified approach.

Dartmouth’s OT team had long utilized the Network Services team’s infrastructure, but they have now expanded their use of the IT-managed network beyond just supervisory layer devices and major equipment to include nearly all use cases, including terminal controls. The facilities team now leverages the same managed switches, monitoring systems, and support staff that handle the university’s enterprise network. Dartmouth’s OT team essentially became a client of central IT, gaining access to a suite of tools—IP address managers, network analyzers, and more—that were never before applied to building systems. These tools supplemented classic OT tools, like Optigo Networks’ Visual BACnet, which offers Dartmouth near-real-time updates on every device within their BACnet network. The payoff was immediate: issues that used to require physical trips to a building and days of packet capture can now be diagnosed in minutes from the operations center (or even from home) using remote diagnostics.

In addition to the convergence of OT and IT practices, the Dartmouth team unlocked operational efficiencies by using open-source and cloud-based tools to manage their building data. Dartmouth has a partnership with ACE IoT Solutions, an independent data layer (IDL) solution provider that leverages open-source frameworks like Eclipse VOLTTRON to aggregate and normalize building data. 

The open-source nature of the tools ACE IoT implements unlocks the ability for customers to solve their own problems. “If I want something in my system fixed, typically I have to buy something… and sometimes there isn't something to buy. And it's actually cheaper and faster for me to do it myself [using open source tools],” stated Plumley.

ACE IoT supported Dartmouth in the development of a comprehensive data model that included all aspects of the converged IT and OT networks. This continuously updated model is machine-readable for simple application of heuristics like duplicate device or network ID detection, while also providing a visualization of the systems involved across the IT and OT domains. Dartmouth and its various vendors and service providers use this model to communicate BACnet network structure, opportunities, and inefficiencies within meetings. In the case of Dartmouth Hall, network improvements made possible by this data model amounted to 35% annual energy savings and $30,000 in saved energy costs.

 BACnet graph networks built to help visualize how Dartmouth’s OT Network Operates

Perhaps most importantly, Dartmouth’s facilities group took advantage of IT expertise instead of fighting it. They now use professional network management practices: managed switches, IP address management tools to allocate addresses systematically, and BACnet performance monitors to watch BAS network traffic. The result is a campus that’s far more resilient to device misbehavior and much more prepared for increased digital tech in their buildings because the underlying network foundation is solid.

Kilroy Realty: Standardizing Building Networks at Portfolio Scale

Kilroy Realty manages ~17 million square feet of commercial real estate on the West Coast. Eight years ago, they developed an IT-experienced technology team to advise and support the building operators and facility managers on how their systems were networked. This led to the re-architecture of every building’s network to an enterprise-grade standard. 

Kilroy now refers to this as a building operational network (BON), which is effectively a parallel enterprise network dedicated to OT, but managed with all the rigor of the IT department. This meant replacing insecure gear and enforcing standards across the entire portfolio. 

“We actually created a network foundation that would require all of our buildings to operate under [it]. 120 buildings had to be fully retrofitted. All non-managed switches had to be ripped out,” Bayron Lopez, former director of operational technology at Kilroy Realty, and now manager of technology integration at Netflix, said. Kilroy deployed managed switches at all sites and set up proper segmentation (VLANs for different systems like HVAC, security, elevators, etc). In short, they laid a strong, standardized IT foundation under every OT system.

Crucially, Kilroy developed an approved hardware and software catalog—internally dubbed the “Killware Matrix” —that all vendors and contractors must follow. If a mechanical contractor needs to add a sensor, it can’t come with some random wireless access point for remote connectivity. Kilroy drastically reduced the variability that often plagues OT environments by strictly limiting the device types and network gear allowed. 

The critical piece of specified equipment in the Killware Matrix was Neeve’s Secure Edge device and software application, the benefits of which are twofold: strong cybersecurity (like unified threat monitoring and the ability to instantly cut off or customize a vendor’s access across all sites if needed) and reliable connectivity (using SD-WAN to prioritize and route traffic). The Secure Edge can also run edge computing applications on-site, which means Kilroy can deploy additional analytics or protocol translation apps at the edge without adding more boxes.

Kilroy’s enterprise-wide view of OT also enabled efficiencies that single-building setups would never allow. They virtualized many on-site servers into a few central data centers. Instead of each building running its own server for software applications like a BAS, Kilroy can host multiple instances on a virtual machine cluster and allow them to communicate back to the sites via the secure SD-WAN provided by Neeve. 

This not only cuts down on hardware and maintenance costs but also makes updates and backups easier (all done in the data center). Lopez noted, “you used to see a bunch of servers at each building. Now we can virtualize that, put it in our data center… and then reduce that cost”. The OT network design also anticipates east-west traffic between buildings. For example, if one building’s chiller plant can serve an adjacent building, or if a campus shares a central utility plant, the OT network allows those systems to talk to each other securely across the portfolio.

Implementing these changes required careful navigation of OT vs IT priorities. “On the IT side, you see something that’s no longer supported, you chuck it out. In the building, you can’t tell someone to rip out equipment because that might be half a million dollars,” Lopez said, underscoring the need for flexibility. Kilroy’s approach was to balance IT standards with OT realities: secure what you can, isolate what you can’t, and budget for gradual upgrades. 

Another key to Kilroy’s success was baking the standards into vendor contracts and new construction. Lopez’s team updates their OT network standards quarterly and works to get them referenced in project specifications. In one case, a general contractor initially balked at the stringent IT requirements, but as Kilroy continued to insist (and invest), the contractor came around and is now proactively implementing the network infrastructure from the design phase. 

Some of Kilroy’s contractors are now proposing where to put IDF closets, how to run fiber between buildings, and which managed switches to install, all in line with Kilroy’s standards. This kind of early adoption is the holy grail of governance: when your partners start doing it before you even ask, you know the practices have taken hold.

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McKesson: Real-Time OT Management at Enterprise Scale

In McKesson’s distribution centers and warehouses, the stakes for OT reliability are enormous. The company's core operations are at risk if the environmental controls or automation systems go down. “If I leave an OT system vulnerable in a distribution center and somebody breaks in and brings down any part of the OT network, that’s McKesson’s revenue stream,” said Drew DePriest, who leads real estate technology at McKesson. “If that goes down, I have no job anymore”. 

This mission-critical nature drove McKesson to blend IT rigor into its OT operations. Unlike Dartmouth, where OT sought out IT tools, at McKesson, it was more like IT came knocking on OT’s door—cybersecurity auditors and compliance teams increasingly scrutinized building systems. DePriest noted that regulations for publicly traded companies like the SOX Act now require quarterly reviews of user access for every system, which is “starting to apply to every OT system as well”. In short, the corporate governance umbrella is expanding to cover building tech, whether OT is ready or not.

One of McKesson’s first moves was to get a handle on OT asset tracking and network access control. Because McKesson’s building systems are connected to the corporate network (there’s no completely separate BAS network), DePriest’s team had “no control over creating VLANs or assigning ports” and had to work through corporate IT for any changes. 

Initially, this led to frustrating delays. DePriest recalled that when he joined, “the big complaint I heard was it takes 6 months to get a static IP for a new [building controller]”. The process was a black box. OT staff would request an IP or new switch port and wait endlessly with “blank stares” as to status. 

To fix this, McKesson created a formal workflow for OT network changes. DePriest literally drew a Visio diagram with the IT network team mapping out each step (from filing a JIRA ticket for a new VLAN to getting approvals) and got everyone to agree on this standardized process. Once implemented, the result was dramatic: the lead time for provisioning a new controller dropped from six months to about three weeks. What was once an informal, siloed request became a documented procedure in IT’s system.

McKesson also borrowed IT change management practices to support governance of the OT network. The team established separate development and production instances for critical OT applications so that new configurations or updates could be tested safely. “We run a change process just like an enterprise IT company would,” DePriest explained, “anytime we need to make a change—if we’re changing IPs, if we’re updating certificates on field controllers—that all starts in dev”. 

McKesson even developed rollback procedures and communication plans for OT updates, mirroring the discipline of an IT change review board but tailored to the realities of building systems. As DePriest shared, these change management practices help his team stay far away from this meme:

To keep track of it all, McKesson turned to data and dashboards. The OT team built a live inventory of OT assets and their network details, integrating it with corporate IT databases and even using business intelligence tools for visibility. In practice, this meant every new device was logged, given the appropriate network credentials, and monitored. 

DePriest created a Power BI dashboard that sits on top of a simple spreadsheet—a low-cost “system” to track devices, IPs, firmware versions, etc., which can be easily shared with both OT and IT stakeholders. The takeaway: fancy software isn’t a prerequisite for OT asset management—the key is having the discipline to maintain the data and make it accessible.

Don’t Take It On Alone

If you're a building owner feeling behind the eight ball compared to these success stories, don’t fret. Not every organization will have the in-house resources of Dartmouth, Kilroy, and McKesson, and that’s where third-party network managers come in. Joe Gaspardone, COO of Montgomery Technologies, joined the Nexus podcast and described a service provider’s approach to helping building owners fill the IT/OT gap. Gaspardone described Montgomery Technologies as a “secure network provider”—essentially a company that designs, installs, and operates the connectivity infrastructure in buildings. (In The Nexus Marketplace, we refer to this category more generally as Network Managers).

For example, a building owner might contract Montgomery Technologies to replace all those non-secure “Best Buy switches” (locations unknown!) with a professionally managed network, implement network access control for building systems, and continuously monitor for threats or anomalies. In essence, Montgomery becomes the “support structure” at the building level for OT and IT, ensuring that moves, adds, and changes to devices are connected with consistent, cybersecure standards.  This outsourcing model can be very attractive for companies with the need to leverage building-wide network and connectivity standards — typically high-rise offices and multifamily properties — where corporate IT is thinly staffed and OT does not have network engineering experience. 

The presence of such solution providers in the market underscores an important point: you don’t have to do everything yourself. It’s about ensuring the expertise is applied, one way or another. Whether by internal upskilling, like Dartmouth’s team learning IT tools, or by hiring specialists, the outcome is a more robust, secure environment for building operations.

Incremental Steps Towards Better Operations

The facility operations industry is often (rightly) cautious, but momentum is building for change. As more success stories emerge and knowledge spreads, it’s becoming easier for the next facility manager or OT engineer to say, “let’s try this at our site.” Whether you manage a college campus, a corporate real estate portfolio, or a single high-rise, the principles remain the same. 

Start at the network layer, bring your allies (IT, vendors, consultants) together, and take incremental steps toward integration. The end game is safer, smarter, and more efficient facilities, with OT leaders who are seen not just as caretakers of equipment but as strategic innovators driving the business forward. That is the future, proven by the work you begin today.

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