A Beginner’s Guide to Recognizing Five Network Denial-of-Service Attacks

Summary

A beginner-focused guide explains how to recognize SYN floods, Smurf, Ping of Death, Teardrop, and Land attacks, highlighting identifying network patterns and basic countermeasures.

Key points

• A SYN flood leaves TCP handshakes incomplete, filling a server’s half-open connection table; suggested defenses include SYN cookies, timeouts, and rate limiting.
• Smurf attacks use spoofed ICMP requests sent to broadcast addresses to amplify replies toward a victim; Fraggle uses UDP instead.
• Ping of Death involves oversized ICMP packets, while Teardrop uses overlapping fragments; the article says patched systems are largely protected.
• Land attacks use packets with matching source and destination IP addresses and ports; modern systems and ingress filtering can block them.
• The attacks target service availability rather than data theft, and distributed denial-of-service traffic is harder to block than traffic from a single source.