# external\_tcp\_44818 **Explanation** The external\_tcp\_44818 NDM flags connections from outside the customer network to servers on the customer network listening on TCP port 44818. Rockwell Automation ICS systems use TCP port 44818. These kinds of systems should never be exposed to the open Internet. **What to Look For** Verify that the server (the source IP in this case) is expected to receive connections from this source (the destination IP in this case) on port 44818. While traffic to this port could be innocuous, very few networks intentionally expose this service to external hosts. This event could false positive in a situation where Netography has not been configured with the appropriate internal network IP address ranges. **Related MITRE ATT\&CK Categories** [Initial Access: Exploit Public-Facing Application, Technique T1190 - Enterprise](https://attack.mitre.org/techniques/T1190) --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://docs.fusion.vectra.ai/detection-models/library/operational-governance/external_tcp_44818.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.