Source Fields

Overview

The source fields describe the originating system, device, or network endpoint associated with an event. They represent identifying and network-related attributes that characterize where an action, connection, or message was initiated. The entity provides a consistent structure for referencing source-side information across heterogeneous platforms and event types.

The source fields have the prefix source_ and describe the originating system or endpoint involved in the event. They are conceptually distinct from the top-level event field named source that may represent the system responsible for sending or forwarding the log message.

Design and Usage

The source entity models conceptual properties of the system or endpoint responsible for originating activity described in an event. Its fields capture device identifiers, network addresses, operating system metadata, and other attributes commonly associated with source context. As a top-level entity, source supports reliable correlation and normalization across diverse logging formats and network environments.

Common Use Cases

  • Associating activity with the device or endpoint that initiated a network connection or system action
  • Normalizing heterogeneous source identifiers for use in detections, analytics, and investigative workflows
  • Tracking attributes of originating systems to support behavioral baselining, asset classification, and forensic analysis

Implementation Notes

As a top-level entity, source represents the complete object describing the originating system or endpoint. Its fields should remain platform-neutral and consistently applied to preserve clarity across event types. If related entities such as destination or network are implied but not explicitly defined, corresponding fields may be included to clarify event semantics and maintain relational integrity.

field field_type description example_values

source_bytes_sent

long

Amount of network data transmitted from the source, measured in bytes.

29834710

source_device_model

keyword

Model designation of the source device.

iPad

source_device_vendor

keyword

Manufacturer associated with the source device.

Apple, ASUS

source_hostname

keyword/lowercase

Hostname of the source system, represented in lowercase.

corpdc01, corpdc01.local, lab01.corpdomain.com

source_id

keyword

Identifier associated with the source device, such as a serial or hardware ID.

09VX93DD

source_ip

ip

IPv4 or IPv6 address assigned to the source.

10.1.2.3, fe80:5cc3:11:4::2c

source_ipv6

ip

IPv6 address assigned to the source.

fe80:5cc3:11:4::2c

source_nat_ip

ip

Translated IP address assigned to the source by a network address translation mechanism.

10.1.2.3, fe80:5cc3:11:4::2c

source_nat_port

integer

Translated network port assigned to the source by a network address translation mechanism.

2384

source_os_name

keyword

Name of the operating system running on the source device.

IOS, Android

source_os_version

keyword

Version value associated with the operating system of the source.

IOS 10.0

source_packets_sent

long

Number of network packets transmitted from the source.

23094823

source_port

integer

Network port used by the source, represented as a value between 0 and 65535.

45392

source_port_iana_name

keyword

IANA-registered service name associated with the source port.

ssh, ftp

source_region

keyword

Geographic or cloud region associated with the source device.

us-east-1

source_type

keyword

Type or classification of the source device.

source_vm_name

keyword

Name of the virtual system associated with the source device.

source_vsys_uuid

keyword

Unique identifier associated with the source virtual system.