User Guide

Required Ports Reference

This reference lists the network paths used by an Audit Service. Unless stated otherwise, connections are initiated by the Audit Service host.

AlloyScan connectivity

Source Destination Protocol Port Purpose
Audit Service host AlloyScan instance TCP 443 Service registration, task communication, and audit data upload over HTTPS.
Audit Service host AWS, Azure, or Google Cloud API endpoints TCP 443 Cloud resource scan and audit over provider APIs.

Windows computers

Windows audit uses PowerShell Remoting over WinRM. When PowerShell Remoting is already enabled on the target, TCP 5985 is the only target port required for scan and audit.

Required when Destination Protocol Port Purpose
PowerShell Remoting is enabled Windows target TCP 5985 WinRM over HTTP for Windows recognition, device identification, and audit.
Domain credentials are used Domain controller TCP 88 Kerberos authentication. Domain authentication fails if this port is unavailable.
Current-user information is collected from Active Directory Domain controller TCP 389 LDAP queries. Audit can continue without this port, but current-user information is not collected.

Enabling PowerShell Remoting remotely

The following ports are needed only when PowerShell Remoting is not enabled and the Audit Service must recognize the Windows target and enable remoting remotely.

Purpose Protocol Port
RPC endpoint mapping TCP 135
Windows recognition TCP 139
SMB communication TCP 445
Enable PowerShell Remoting remotely UDP 135
Detect a remote Audit Agent UDP 139

The firewall must also allow RPC traffic used for Windows recognition, device identification, and remote PowerShell Remoting setup.

For Windows domain constraints, see Supported Targets.

Linux and macOS computers

Source Destination Protocol Port Purpose
Audit Service host Linux or macOS target TCP 22 by default SSH access for agentless audit. Use the port configured in the Linux and macOS credential if the target uses a non-standard SSH port.

Hypervisors

Target Protocol Port Purpose
Microsoft Hyper-V host TCP 5985 WinRM for Hyper-V host management and audit.
VMware ESXi host TCP 80 HTTP communication.
VMware ESXi host TCP 443 HTTPS communication.
VMware ESXi host TCP 902 ESXi recognition.
Xen or Citrix Hypervisor host TCP 22 by default SSH access. Use the port configured in the Hypervisor credential if the host uses a non-standard SSH port.

Network devices

Target Protocol Port Purpose
SNMP device UDP 161 SNMPv1, SNMPv2c, or SNMPv3 data collection.
Printer TCP 9100 Printer recognition in environments where SNMP alone does not identify the device.
NAS device TCP 139 NAS recognition.

Printer audit data is collected through SNMP on UDP 161. TCP 9100 is used only for printer recognition when required.

Network scanning

Protocol Port Purpose
UDP 53 DNS resolution.
UDP 137 NetBIOS name resolution.
UDP 138 NetBIOS communication.
ICMPv4 Not applicable Reachability checks such as ping. Recommended for optimal discovery.