This detection has been marked experimental by the Splunk Threat Research team. This means we have not been able to test, simulate, or build datasets for this detection. Use at your own risk. This analytic is NOT supported.

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The following analytic detects ARP Poisoning attacks by monitoring for Dynamic ARP Inspection (DAI) errors on Cisco network devices. It leverages logs from Cisco devices, specifically looking for events where the ARP inspection feature has disabled an interface due to suspicious activity. This activity is significant because ARP Poisoning can allow attackers to intercept, modify, or disrupt network traffic, leading to potential data breaches or denial of service. If confirmed malicious, this could enable attackers to perform man-in-the-middle attacks, compromising the integrity and confidentiality of network communications.

  • Type: TTP
  • Product: Splunk Enterprise, Splunk Enterprise Security, Splunk Cloud

  • Last Updated: 2024-05-12
  • Author: Mikael Bjerkeland, Splunk
  • ID: b44bebd6-bd39-467b-9321-73971bcd1aac




ID Technique Tactic
T1200 Hardware Additions Initial Access
T1498 Network Denial of Service Impact
T1557 Adversary-in-the-Middle Credential Access, Collection
T1557.002 ARP Cache Poisoning Credential Access, Collection
Kill Chain Phase
  • Delivery
  • Actions On Objectives
  • Exploitation
  • DE.CM
  • CIS 13
`cisco_networks` facility="PM" mnemonic="ERR_DISABLE" disable_cause="arp-inspection" 
| eval src_interface=src_int_prefix_long+src_int_suffix 
| stats min(_time) AS firstTime max(_time) AS lastTime count BY host src_interface 
| `security_content_ctime(firstTime)`
| `detect_arp_poisoning_filter`


The SPL above uses the following Macros:

:information_source: detect_arp_poisoning_filter is a empty macro by default. It allows the user to filter out any results (false positives) without editing the SPL.

Required fields

List of fields required to use this analytic.

  • _time
  • facility
  • mnemonic
  • disable_cause
  • src_int_prefix_long
  • src_int_suffix
  • host
  • src_interface

How To Implement

This search uses a standard SPL query on logs from Cisco Network devices. The network devices must be configured with DHCP Snooping (see https://www.cisco.com/c/en/us/td/docs/switches/lan/catalyst2960x/software/15-0_2_EX/security/configuration_guide/b_sec_152ex_2960-x_cg/b_sec_152ex_2960-x_cg_chapter_01101.html) and Dynamic ARP Inspection (see https://www.cisco.com/c/en/us/td/docs/switches/lan/catalyst2960x/software/15-2_2_e/security/configuration_guide/b_sec_1522e_2960x_cg/b_sec_1522e_2960x_cg_chapter_01111.html) and log with a severity level of minimum "5 - notification". The search also requires that the Cisco Networks Add-on for Splunk (https://splunkbase.splunk.com/app/1467) is used to parse the logs from the Cisco network devices.

Known False Positives

This search might be prone to high false positives if DHCP Snooping or ARP inspection has been incorrectly configured, or if a device normally sends many ARP packets (unlikely).

Associated Analytic Story


Risk Score Impact Confidence Message
25.0 50 50 tbd

:information_source: The Risk Score is calculated by the following formula: Risk Score = (Impact * Confidence/100). Initial Confidence and Impact is set by the analytic author.


Test Dataset

Replay any dataset to Splunk Enterprise by using our replay.py tool or the UI. Alternatively you can replay a dataset into a Splunk Attack Range

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