L2.12 Static vs Dynamic IP for Industrial Automation | Why OT Networks Require Static Addressing
In this video, we explore one of the most fundamental topics in OT networking: the difference between static and dynamic IP addressing, also known as DHCP. Understanding this distinction is critical for anyone working in industrial automation, manufacturing IT, or controls engineering. While DHCP allows our home and office devices to automatically receive IP addresses from a router, industrial systems require a much more deliberate and structured approach. Static IP addressing ensures that critical devices such as PLCs, HMIs, and VFDs communicate reliably and consistently, without the unpredictability of dynamically assigned addresses.
We start by reviewing how DHCP works in a typical home or office network, where a modem or router dynamically assigns addresses from a predefined pool. This setup makes it easy to connect laptops, mobile phones, and PCs without any manual configuration. Then we contrast this with how OT networks operate, where deterministic communication and reliability are key. We look at why unmanaged switches cannot assign IP addresses, why DNS servers are rarely found on the plant floor, and how this impacts both configuration and troubleshooting.
By the end of this video, you will clearly understand why static addressing remains the standard in industrial environments, how to configure it correctly, and what risks arise when DHCP is mistakenly introduced into OT systems. This is part of Joltek’s OT Networking Fundamentals series, designed to help you master real plant-floor networking concepts that go beyond theory. If you want to deepen your understanding of OT networking, be sure to explore our related materials and courses below.
For a complete guide on manufacturing systems, modernization, and digital transformation strategies, visit Joltek’s blog and services pages:
https://www.joltek.com/blog/manufactu...
https://www.joltek.com/services/servi...
https://www.joltek.com/blog/modern-pl...
Timestamps
00:00 Introduction to static vs dynamic addressing
00:28 Why home networks use DHCP and OT networks do not
01:25 Understanding how DHCP pools assign IPs automatically
02:23 Common home network example and IP allocation explanation
03:22 Configuring static and dynamic IPs and when to use each
04:17 Why DHCP is not practical for PLCs and HMIs
05:17 Role of DNS servers and why they are rarely used in OT
05:47 How static IP configuration ensures deterministic communication
06:42 Future outlook and considerations for hybrid architectures