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.
Internet Protocol Security (IPsec) is a protocol suite for secure Internet Protocol (IP) communications by authenticating and encrypting each IP packet of a communication session.Psec is officially standardised by the Internet Engineering Task Force (IETF) in a series of Request for Comments documents addressing various components and extensions. It specifies the spelling of the protocol name to be IPsec.