Scapy is a powerful Python library used for network packet manipulation and analysis. In this guide, we will explore how to build network scanners using Python and Scapy to perform tasks like network discovery, packet sniffing, and vulnerability assessment.
Setting Up Scapy
The first step is to install Scapy. Scapy can be installed via pip and may require additional dependencies depending on your operating system.
# Install Scapy
pip install scapy
Network Discovery
Scapy can be used to create a simple network scanner to discover active hosts in a network. This involves sending ARP requests and monitoring responses.
# Python code for network discovery using Scapy
from scapy.all import ARP, Ether, srp
def network_scan(ip):
arp_request = ARP(pdst=ip)
broadcast = Ether(dst="ff:ff:ff:ff:ff:ff")
arp_request_broadcast = broadcast / arp_request
answered_list = srp(arp_request_broadcast, timeout=1, verbose=False)[0]
clients = []
for element in answered_list:
client_dict = {"ip": element[1].psrc, "mac": element[1].hwsrc}
clients.append(client_dict)
return clients
# Replace '192.168.1.1/24' with the target network
scan_results = network_scan('192.168.1.1/24')
for client in scan_results:
print(client)
Packet Sniffing
Packet sniffing involves capturing network packets in real-time. Scapy provides functionalities to filter and analyze these packets.
# Python code for packet sniffing using Scapy
from scapy.all import sniff
def packet_callback(packet):
print(packet.show())
# Start sniffing packets
sniff(prn=packet_callback, store=False)
Vulnerability Assessment
You can also use Scapy to assess vulnerabilities, such as inspecting packets for anomalies or testing networks for susceptibility to specific attack vectors.
Scapy is a versatile tool for network analysis and security testing. With Python and Scapy, you can build custom network scanners tailored to your specific requirements, ranging from basic network discovery to complex security assessments.