DoS and Layer 2 Attacks

Imagine a highly efficient, automated mail-sorting facility. Every package that arrives has a specific destination, and the sorting machines use a precise internal ledger to route each parcel to the correct delivery truck. If the system is functioning perfectly, mail moves swiftly and securely. But what happens if an adversary intentionally floods the loading dock with a million bogus packages? What if they forge the internal ledgers, or trick the sorters into dropping packages into the wrong delivery bins? The entire facility grinds to a halt, or worse, sensitive mail is handed directly to a thief.

Local and wide area networks operate on the exact same principles. The protocols that direct our traffic were designed for efficiency and reliability, often under the assumption that the devices participating in the network are trustworthy. Attackers study these protocols, understand their mechanical behaviors, and exploit their blind spots.

To defend a network infrastructure, you must first deeply understand how it can be broken.