How can you configure a TCP/IP network to minimize DDoS attacks?

1 Enable TCP SYN cookies

One of the most common types of DDoS attacks is the SYN flood, which exploits the TCP handshake process to consume the resources of the target server. The attacker sends a large number of SYN packets, which are requests to initiate a connection, but never completes the handshake by sending the final ACK packet. This leaves the server waiting for the ACKs and filling up its connection queue. To prevent this, you can enable TCP SYN cookies, which are a way of verifying the legitimacy of the SYN packets. TCP SYN cookies are special values that the server embeds in the SYN-ACK packets it sends back to the clients. The values are based on a cryptographic hash of the IP address, port number, and a secret key. If the client responds with a valid SYN cookie, the server accepts the connection. Otherwise, it ignores the packet.

2 Use firewall rules and filters

Another way to configure your TCP/IP network to minimize DDoS attacks is to use firewall rules and filters to block or limit the traffic from suspicious sources or patterns. For example, you can use IP filtering to deny access to specific IP addresses or ranges that are known to be malicious or irrelevant. You can also use port filtering to block or restrict traffic on certain ports that are not needed for your network services. Additionally, you can use packet filtering to inspect the headers and payloads of the packets and reject those that are malformed, spoofed, or contain malicious content.

3 Implement rate limiting and throttling

Rate limiting and throttling are techniques that can help you control the amount and speed of traffic that your network can handle. Rate limiting sets a maximum number of requests or packets that a client or source can send to your network in a given period of time. If the limit is exceeded, the network drops or delays the excess traffic. Throttling reduces the bandwidth or processing power allocated to a client or source that is sending too much traffic or consuming too much resources. Both techniques can help you prevent your network from being overwhelmed by DDoS attacks and prioritize the legitimate traffic.