IP spoofing involves altering the source IP address in data packets so they appear to come from a different device or network than they actually do. This happens at the network layer, where attackers manipulate packet headers before sending them across the internet.
How it works: Every data packet sent over the internet contains header information including a source IP address. Attackers use specialised tools to craft packets with false source addresses, making it difficult for recipients to trace the true origin of the traffic.
Common attack types:
- DDoS attacks: Attackers flood a target with traffic from spoofed addresses, making the assault harder to block and trace.
- Man-in-the-middle attacks: An attacker intercepts and alters communications whilst appearing to be a trusted source.
- Session hijacking: Spoofed packets can trick systems into accepting unauthorised commands from what appears to be a legitimate connection.
Why it matters: IP spoofing undermines trust in network communications and enables various cybercrimes including fraud, data theft, and service disruption. Networks that rely solely on IP addresses for authentication become vulnerable.
Protection measures: Organisations defend against IP spoofing through ingress and egress filtering, which blocks packets with suspicious source addresses. Authentication protocols beyond simple IP verification, such as cryptographic signatures, provide stronger security. Many modern systems also implement reverse DNS lookups and packet rate limiting.
For home users, this remains largely a network-level threat, though awareness helps when evaluating business-grade security products and understanding why multi-factor authentication matters.