A security-procuring method for making an item of communications equipment (E) secure, said item of communications equipment comprising an operating system core (K) and a set of software applications (A), said core including at least one IPv6 protocol stack (PS) making it possible to transmit incoming data packets from an input port (P.sub.IN) to an application (A) and to transmit outgoing data packets from an application (A) to an output port (P.sub.OUT), said protocol stacks including a set of interfaces (H.sub.PRE, H.sub.IN, H.sub.OUT, H.sub.POST) organized to enable external modules connected to them to access said data packets transmitted by said at least one protocol stack at determined points associated with said interfaces. Said method is characterized in that an input module (M.sub.IN) and an output module (M.sub.OUT) are connected respectively to an input interface (H.sub.IN) and to an output interface (H.sub.OUT) of said core (K), and in that said modules select, analyze, and, if necessary, modify the data packets of the Network Discovery Protocol (NDP), in compliance with the Secure Neighbor Discovery (SEND) mechanism.