Adversaries may block access to Ethernet communications to prevent instructions or configurations messages from reaching target systems and devices. Ethernet connections allow for communications between IT and OT systems and devices. Blocking Ethernet communications may also block command and reporting messages.(Citation: Bonnie Zhu, Anthony Joseph, Shankar Sastry 2011) An adversary may block Ethernet communications by disabling network interfaces, [Service Stop](https://attack.mitre.org/techniques/T0881), or conducting an [Adversary-in-the-Middle](https://attack.mitre.org/techniques/T0830) attack and dropping the network traffic.
Architect sections of the network to isolate critical systems, functions, or resources. Use physical and logical segmentation to prevent access to potentially sensitive systems and information. Use a DMZ to contain any internet-facing services that should not be exposed from the internal network. Restrict network access to only required systems and services. In addition, prevent systems from other networks or business functions (e.g., enterprise) from accessing critical process control systems. For example, in IEC 62443, systems within the same secure level should be grouped into a zone, and access to that zone is restricted by a conduit, or mechanism to restrict data flows between zones by segmenting the network. (Citation: IEC February 2019) (Citation: IEC August 2013)
M0810Out-of-Band Communications ChannelHave alternative methods to support communication requirements during communication failures and data integrity attacks. (Citation: National Institute of Standards and Technology April 2013) (Citation: Defense Advanced Research Projects Agency)
M0807Network AllowlistsNetwork allowlists can be implemented through either host-based files or system hosts files to specify what connections (e.g., IP address, MAC address, port, protocol) can be made from a device. Allowlist techniques that operate at the application layer (e.g., DNP3, Modbus, HTTP) are addressed in [Filter Network Traffic](https://attack.mitre.org/mitigations/M0937) mitigation.
MITRE ATT&CK® is a registered trademark of The MITRE Corporation. © 2026 The MITRE Corporation. This work is reproduced and distributed with the permission of The MITRE Corporation.