The disclosed apparatus may include (1) a storage device that stores a set of cookies that facilitate authenticating packets received from a node within a network and (2) a processing unit communicatively coupled to the storage device, wherein the processing unit (A) receives at least one packet from the node, (B) identifies a cookie included in the packet received from the node, (C) searches the set of cookies stored in the storage device for the cookie included in the packet received from the node, (D) identifies, during the search of the set of cookies, the cookie included in the packet and (E) protects against a DoS attack by authenticating the legitimacy of the packet based at least in part on the cookie included in the packet being identified in the set of cookies stored in the storage device. Various other apparatuses, systems, and methods are also disclosed.