arp-spoo-atta-smlt

name	arp-spoo-atta-smlt
description	Simulates ARP spoofing attacks in authorized lab or pentest environments using arpspoof, Ettercap, and Scapy to demonstrate man-in-the-middle risks, test network detection capabilities, and validate ARP inspection countermeasures.
domain	cybersecurity
subdomain	network-security
tags	["network-security","arp-spoofing","mitm","ettercap","layer2-attack"]
version	1.0
author	mahipal
license	Apache-2.0
nist_csf	["PR.IR-01","DE.CM-01","ID.AM-03","PR.DS-02"]

Performing ARP Spoofing Attack Simulation

When to Use

• Testing whether network switches and infrastructure properly implement Dynamic ARP Inspection (DAI)
• Demonstrating man-in-the-middle attack risks to stakeholders during authorized security assessments
• Validating that network monitoring tools (IDS/IPS, SIEM) detect ARP cache poisoning attempts
• Assessing the effectiveness of port security, 802.1X, and VLAN segmentation controls
• Training SOC analysts to recognize ARP spoofing indicators in network traffic

Do not use on production networks without explicit written authorization and a rollback plan, against networks carrying critical or life-safety traffic, or as a denial-of-service attack vector.

Prerequisites

• Written authorization specifying in-scope network segments for ARP spoofing simulation
• Kali Linux or similar penetration testing distribution with arpspoof, Ettercap, and Scapy installed
• Direct Layer 2 access to the target network segment (same VLAN as target hosts)
• IP forwarding knowledge and ability to enable/disable packet forwarding on the attacker machine
• Wireshark or tcpdump for capturing traffic to verify interception
• Isolated lab environment or approved production test window

Legal Notice: This skill is for authorized security testing and educational purposes only. Unauthorized use against systems you do not own or have written permission to test is illegal and may violate computer fraud laws.

Workflow

Step 1: Enumerate the Target Network Segment

# Discover hosts on the local subnet
nmap -sn -PR 192.168.1.0/24 -oG arp_discovery.txt

# Identify the default gateway
ip route show default
# Output: default via 192.168.1.1 dev eth0

# Identify target hosts and their MAC addresses
arp-scan -l -I eth0

# Verify the current ARP table
arp -a

# Note the gateway IP (192.168.1.1) and target host IP (192.168.1.50)
# Record their legitimate MAC addresses for verification and cleanup

Step 2: Enable IP Forwarding

# Enable IPv4 forwarding to relay packets between victim and gateway
sudo sysctl -w net.ipv4.ip_forward=1

# Verify forwarding is enabled
 /proc/sys/net/ipv4/ip_forward



 sysctl -w net.ipv4.conf.all.send_redirects=0
 sysctl -w net.ipv4.conf.eth0.send_redirects=0