What role do firewalls and intrusion detection/prevention systems (IDS/IPS) play in UDP DDoS mitigation?

Firewalls can be configured to filter UDP traffic based on source IP, port, or other characteristics. IDS/IPS systems can detect malicious UDP traffic patterns and automatically block or mitigate the attack. While they can provide a first line of defense, they are often insufficient to handle large-scale UDP DDoS attacks and are best used in conjunction with other mitigation techniques.