How can I use a firewall to protect against IP address DDoS attacks?

Firewalls can be configured to rate limit traffic from specific IP addresses, block traffic from known malicious IPs (using IP reputation lists), and filter traffic based on packet characteristics (e.g., rate of incoming packets). Stateful firewalls can also detect and block connection attempts that don't conform to standard TCP handshake patterns, which is a tactic often used in SYN floods.