The document discusses various techniques for mitigating DDoS attacks, including: - Using firewalls and intrusion detection systems to filter malicious traffic and detect attacks. - Hardening systems by tuning operating systems, applications, and network devices to prevent exhaustion of resources. - Implementing defense in depth across multiple network layers and monitoring logs to identify attacks. - Leveraging cloud-based DDoS mitigation services for very large attacks. - Regularly testing defenses by simulating attacks to ensure effectiveness.