> For the complete documentation index, see [llms.txt](https://docs.fusion.vectra.ai/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.fusion.vectra.ai/detection-models/library/reconnaissance/esxi_internal_slp_scan.md).

# esxi\_internal\_slp\_scan

**Explanation**

The esxi\_internal\_slp\_scan NDM is designed to detect Port 427 internal scanning activities on ESXi servers. This is a common port used for service location protocol, and by scanning this port, attackers can detect open services on the network. This NDM is triggered when such scanning activities are detected, indicating a potential security threat.

**What to Look For**

To examine the results of the esxi\_internal\_slp\_scan NDM Event, network administrators should look for any internal scanning activities on Port 427, particularly if they are detected on ESXi servers. It is important to investigate further to determine the source of the scanning activity and whether it is malicious in nature. Remediation steps should be taken immediately to secure the network and prevent any further potential exploits.

**Related MITRE ATT\&CK Categories**

[Discovery: Network Service Discovery, Technique T1046 - Enterprise](https://attack.mitre.org/techniques/T1046)


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