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.
IP Security (IPSec) is mandatory for IPv6implementations. Given that IPv6 will be dominated by commercial off the shelf (COTS)software products, many in the DoD community will have a software encryption capability attheir disposal.