Factories in Sanand, Sriperumbudur, Pune, and Noida run like software teams now. You push updates to lines, add sensors, open OEM VPNs, and sync data to the cloud. Each move adds speed and adds risk. A flat network and stale rules turn small errors into downtime. You need a policy that tracks assets, inspects industrial protocols, and respects latency. This guide shows how a managed firewall run delivers that without slowing production.
In Brief
Your plant runs on data. Robots, PLCs, sensors, MES, and SaaS all talk at once. Attackers know this. You can buy more boxes, or you can buy a managed run that keeps production safe without slowing the line.
Why Factories Face New Cyber Risk
Industry 4.0 connects OT and IT. You add PLCs with Ethernet, cameras on the line, AGVs on WiFi 6, and analytics in the cloud. Every new device and API expands the blast radius. A single flat network turns a small error into plant-wide downtime. You need tight segmentation, clean egress, and inspection that respects real-time traffic.
Start with a clear map of where risk lives in your plant.
The Smart Plant Risk Map
- OT zones, PLCs, HMIs, RTUs, safety controllers
- Industrial protocols, Modbus, PROFINET, OPC UA, EtherNet/IP
- IT and cloud, ERP, MES, historian, data lakes, SaaS
- Edge and IIoT, gateways, sensors, cameras, AGVs
- Thirdparties, OEM vendors, system integrators, maintenance crews
Ask yourself, which flows must always pass, which should pass only during a change window, and which should never leave the cell.
What Managed Firewall Run Changes on the Shop Floor
You keep policy intent and final say. Proactive runs the operation as a Cisco Powered service so your teams can build and run plants.
- Segmentation by design. Zones and conduits mapped to lines and cells. No flat networks. OT stays isolated from IT except for approved conduits.
- Industrial DPI. Applicationlayer control for Modbus, OPC UA, and PROFINET. Allow lists instead of broad ports. Detect function codes that should never appear.
- TLS inspection, safe by default. Selective decrypt for IT web flows. Do not decrypt PLC or clinical-style device portals. Monitor break rate. Keep latency stable.
- Egress control. DNS security and geocontrols for risky regions. No unknown ASNs. SaaS access pinned to known domains.
- Change discipline. Prechecks, tagged owners, timebound exceptions, and tested rollback. Changes land in planned windows, day or night.
- Evidence on tap. Logs and reports mapped to ISO 27001 and CERTIn controls. Evidence packs produced on short notice.
Day One in Sanand: What Good Looks Like
07:30, Shift Handover
The plant IT head reviews the overnight digest. Two blocked attempts to reach unknown ASNs from a vision PC, both quarantined. No impact on OEE. The dashboard shows rule age by cell and a list of objects due for retirement.
12:00, Vendor Maintenance
The OEM needs access to a packaging line PLC. A time-bound exception opens a conduit to a specific IP and function set. The window is 90 minutes. Session logging is on. When work ends, the rule expires. No stale access on Monday.
16:00, Analytics Push
Engineering syncs MES with a cloud data lake. The managed run checks the egress list, allows only the required endpoints, and drops unknown regions. A drift alert would raise a ticket; none appear.
18:00, Review
Operations and security meet for 15 minutes. They track policytoincident ratio, rule age, change success, mean time to detect, and mean time to respond. Miss a target, assign an action.
Architecture That Respects Latency and Uptime
- Zones and conduits. Follow ISA/IEC 62443. Group like assets, then control each conduit with allow lists.
- Deterministic paths. Keep time-sensitive PLC traffic inside the cell. Do not subject it to heavy decryption. Use industrial DPI instead.
- East-west controls. Inspect traffic between cells. Stop lateral movement early. Flag new talkers and unapproved protocols.
- Identity in OTfriendly form. Tag assets and users. Use role-based controls where feasible, with device posture signals from your management stack.
- Cloud edges. Treat gateways and data lake links as first-class conduits with their own rules and monitoring.
The Five Outcomes That Matter to a Plant Head
- Fewer incidents. Detect and block risky flows before they touch controllers.
- Faster change. Maintenance windows meet the clock, with rollback ready.
- Stable latency. Inspection matches traffic, so production does not stall.
- Clean egress. No surprise calls to unknown regions, SaaS stays pinned.
- Auditready. Evidence packs map to ISO 27001 and CERTIn, with owners and timestamps.
The 30-Day Improvement Plan
- Week 1. Baseline rules per line and cell. Remove duplicates and shadow entries. Tag owners.
- Week 2. Implement a selective TLS policy. Decrypt IT web flows, exclude PLC portals. Check the break rate daily.
- Week 3. Build zone and conduit maps for two lines. Apply allow lists for Modbus and OPC UA.
- Week 4. Close the loop with identity and endpoint signals where feasible. Publish weekly metrics. Plan the next two lines.
Case Study, Chennai Auto Components Cluster
A tier2 supplier ran a flat network across three lines. A misconfigured PC started talking to PLCs on the weekend. The managed run moved the plant to zones and conduits, enforced Modbus function allow lists, and set egress rules to block unknown ASNs. In eight weeks, incidents fell by half, change success rose to 98 per cent, and unplanned downtime from network events dropped to near zero.
Case Study, Pune Discrete Manufacturing
A fast-growing line added cameras and AGVs. Alert noise rose and TLS errors hit dashboards. We introduced tag-based policy, rate-limited chatty systems, and selective decryption for IT flows. Mean time to detect fell from 80 minutes to 10 minutes. User tickets dropped by about 40 per cent. Production hit weekly output targets without delays.
Tooling That Fits the Floor
- Shared console. You keep full read and role-based write. Every change tags a requester and an owner.
- Templates per site type. Head office, plant, cell. Deviations create alerts.
- Runbooks. Prechecks, planned windows, rollback. No firefights.
- Evidence packs. Produced on short notice, mapped to ISO 27001 and CERTin control statements.
- Metrics. Policytoincident ratio, rule age, change success, mean time to detect, and mean time to respond.
Reporting in India
CERTIn requires you to report specified incidents within six hours of becoming aware. You need logs, timelines, and contacts ready. (CERTIn Directions, 28 Apr 2022)
What to Ask Before You Sign
- Which assets and conduits will you segment first, and in what order
- Which protocols will you inspect with DPI, and which will stay outside TLS decrypt
- How will you tie firewall signals to identity and device posture, with what runbooks
- What weekly metrics will you publish, and what actions follow a miss
- How fast can you produce ISO 27001 and CERTIn evidence for an audit or report
Why Proactive for Industry 4.0
Proactive operates the run as a Cisco Powered service. You keep control and final say.
What we bring to plants:
- Named run team with OT experience across discrete, auto components, and FMCG
- Segmentation by lines and cells with ISA/IEC 62443 discipline
- Industrial DPI for Modbus, OPC UA, PROFINET, EtherNet/IP
- Selective TLS policy that protects bandwidth and stops blind spots
- Time-bound vendor access SOPs, with autoexpiry and full audit trail
- Evidence packs mapped to ISO 27001 and CERTIn, ready on short notice
- Weekly metrics, owners, and action lists, so improvements keep shipping
Your Next Step
Book a 30-minute consultation with Proactive. We will review your lines and cells, your current rules, and your change windows. You will get practical steps to reduce risk and keep output on target.
FAQs
What is OT segmentation?
Grouping assets into zones and controlling conduits between them. Follow ISA/IEC 62443. Use allow lists for protocols and function codes.
Do we decrypt PLC traffic?
No. Keep PLC and device portals out of TLS decrypt. Decrypt IT web flows. Monitor break rate.
What does CERT-In require?
Report specified incidents within six hours of becoming aware. Keep logs, timelines, and contacts ready.
What metrics prove a managed run works?
Policy-to-incident ratio, rule age, change success, mean time to detect, mean time to respond.
