Network segmentation is a cybersecurity and network design practice that separates an organization’s network into smaller, controlled zones (segments) to limit access, reduce attack spread, and protect critical systems. In EV charging, segmentation helps secure the paths between chargers, site equipment, the CPMS, payment systems, and corporate IT—so a compromise in one area does not expose the entire environment.
Why network segmentation matters in EV charging
Charging networks combine operational technology (OT) and IT with remote access, payments, and field connectivity—making them attractive targets. Segmentation helps to:
– Prevent lateral movement from a compromised charger or router to other systems
– Protect sensitive systems (billing, user data, operator admin portals)
– Reduce the impact of malware and misconfiguration at one site
– Improve compliance posture (security audits, incident response readiness)
– Support safer third-party access for installers and maintenance partners
Common segmentation zones in charging ecosystems
A practical EV charging segmentation model often includes:
Charger/OT segment
– EV chargers, local controllers, gateways, metering, and site sensors
– Restricted outbound communication to required endpoints (CPMS, NTP, DNS)
– No direct inbound access from the public internet
Site services segment
– Local site LAN devices (switches, routers, CCTV, access control, building systems)
– Segmented from chargers unless explicitly needed (e.g., shared EMS integration)
Corporate IT segment
– Employee laptops, internal servers, office Wi-Fi
– Strong separation from charging OT and payment systems
Payments and finance segment
– Payment terminals, PSP connections, settlement tools, invoicing systems
– Additional controls due to PCI-related risk and fraud exposure
Management and admin segment
– CPMS admin access, monitoring dashboards, maintenance tools
– Protected with MFA, least privilege, and audit logging
How segmentation is implemented
Network segmentation can be done using:
– VLANs and separate subnets for each zone
– Firewall rules and allow-listing between zones (default deny)
– VPNs or private APNs for charger connectivity (instead of public internet exposure)
– Zero-trust access controls (identity-based policies and device posture checks)
– Separate Wi-Fi networks for staff vs operational equipment
– Site-to-cloud architectures where chargers only initiate outbound secure connections
Best practices for segmentation in EV charging sites
– Use least privilege: only allow the minimum ports and endpoints needed (often OCPP over TLS)
– Prevent direct charger-to-charger communication unless required
– Restrict remote admin to controlled channels (VPN, bastion host)
– Enforce strong identity controls: RBAC + MFA for admin portals
– Monitor and log traffic between segments; alert on anomalies
– Keep site routers and gateways hardened and patched; disable unused services
– Document segmentation design for commissioning and security audits
Common pitfalls
– Putting chargers on the same flat network as guest Wi-Fi or office devices
– Leaving default credentials on routers, switches, or charger service ports
– Allowing broad inbound access “for convenience” during commissioning
– No change control: firewall rules drift over time and become permissive
– Poor inventory and visibility (unknown devices connected to OT networks)
Related glossary terms
Firewall segmentation
Cybersecurity audits
Incident response plan
Multi-factor authentication (MFA)
Role-based access control (RBAC)
OCPP
Data encryption
Intrusion detection system (IDS)
Intrusion prevention system (IPS)
Secure update pipeline