The LD50 of nicotine is 50 mg/kg for rats and 3 mg/kg for mice. 0.5-1.0 mg/kg can be a lethal dosage for adult humans, and 0.1 mg/kg for children.
IPSec is a suite of protocols that provide security services at IP layer of TCP/IP stack i.e. Network Layer in OSI model. As Andy Lemke mentioned, IPSec suite comprises of two protocols to offer security to. 1. AH - Authentication Header Protocol.(Protocol no: 51) 2. ESP - Encapsulation of security payload Protocol.
The 3rd layer in the OSI model. Protocols in the network layer translate network addresses into their physical counterparts and decide how to route the data from sender to receiver. Data Link Layer. 2nd layer of the OSI model, concerned with protocols and transferring data frames between network nodes. This layer is divided into two sub layers: The logical link control (LLC) sublayer and the Media Access Control (MAC) sublayer.