Every industry with a control network has a line to hold.
Wherever a business network meets the systems that run a process, a few firewall rules decide what can cross. Pick an industry to see where that line usually sits, one crossing that should not be there, and the rules it answers to.
- ManufacturingStop one bad laptop from stopping the line.
- Water and wastewaterKeep the treatment plant off the office network.
- Oil and gasKeep the pipeline running when IT has a bad day.
- Electric powerSee every firewall rule into the Electronic Security Perimeter.
- Pharmaceuticals and life sciencesProtect the batch, not just the network.
- Defense manufacturingShow the shop floor is scoped, not forgotten.
- Ports and maritimeGet terminal segmentation ready before the Coast Guard asks.
- Rail and transitKeep passenger systems away from signaling.
- Warehousing and logisticsKeep the dock moving when the office network goes down.
Oil and gas
Pipeline operators are asked to show that OT keeps running if IT is compromised. SegAudit shows each rule that ties gas control to the business network, how ready each site is to isolate, and the change that cuts the tie.
What crosses the line in oil and gas
Each one is a finding ranked by risk, with the rule that allows it, the hosts that used it when a traffic log is loaded, and the change that closes it.
- VPN users on the compressor network
Anyone on the corporate VPN can reach compressor station controllers.
- A shared file server across the boundary
Gas control maps a file share that also lives on the business network, so an IT outage reaches OT.
- Isolation that would cut operations
Flows the control room needs every day still run through IT, so isolating OT would stop them.
- Broad rules from the business network
Rules that allow a whole IT subnet into SCADA when a few hosts used them.
Illustrative examples of what an audit can find. They are not from a customer.
The rules oil and gas answers to
SegAudit judges the controls a firewall's evidence can speak to as supported, partial or gap, and shows each one again after the change. It helps you assess segmentation; it does not certify compliance.
| Rule | What it asks of segmentation | Judged from the evidence |
|---|---|---|
| TSA Security Directive Pipeline-2021-02G | Segmentation policies and controls so OT can keep running if IT is compromised, and access control for OT systems. | 5 controls |
| IEC 62443-3-3 | Zones and conduits: network segmentation (SR 5.1), zone boundary protection (SR 5.2) and least functionality. | 9 controls |
| NIST CSF 2.0 | Networks protected from unauthorized logical access (PR.IR-01), asset inventories and log monitoring. | 10 controls |
| NIS2 Article 21(2) | Cybersecurity risk-management measures for essential and important entities in the EU. | 6 controls |
| UK NCSC CAF 4.0 | Secure design and access control for operators of essential services in the UK. | 9 controls |
Control by control in the frameworks overview. Confirm the versions in force for your audit period.
Who runs the audit
The same audit either way. What differs is who approves the change.
Asset owners
Your own firewall team runs the audit on its own sites, every quarter, and approves each change through its own change process. Priced per site with the Asset Owner edition.
For asset ownersConsultants
You assess a client's sites and deliver the findings and the fix under your firm's letterhead. The client's team approves. Professional or Engagement.
For consultantsSee what crosses the line on your own firewalls.
Export a firewall configuration, add a traffic log if you have one, and read the findings on your own workstation. Nothing leaves it, and SegAudit never connects to your network.
Step-by-step export guides, for customers and trial holders: Palo Alto, FortiGate, Cisco ASA, Cisco FTD, Check Point.