hping3

Overview

hping3 is a command-line TCP/IP packet crafter. Unlike ping (ICMP only), hping3 can send TCP, UDP, and raw IP packets with any flag combination, arbitrary payloads, spoofed sources, and fragmentation — useful for firewall auditing, ACL testing, reachability probes where ICMP is filtered, and low-level network experiments on your own infrastructure. It is interactive and scriptable.

Instructions

Step 1: Basic TCP/UDP/ICMP Probes

# TCP SYN ping to port 443 — works even when ICMP is dropped
sudo hping3 -S -p 443 -c 3 example.com
# -S: SYN flag
# -p: destination port
# -c: packet count

# TCP ACK ping — often passes stateful firewalls that drop SYN
sudo hping3 -A -p 80 -c 3 target.local