Ans :
IPSec is a framework for ensuring secure private communications over IP networks. IPSec provides security for transmission of critical and sensitive information over unprotected networks such as the Internet. lpsec VPNs use the services defined within Ipsec to ensure confidentiality, Integrity, and authenticity of data communications over the public network, like Internet. IPSec operates at the network layer, protecting arid authenticating IP packets between participating IPSec devices. The IPSec provides the following network security services.
1. Data Confidentiality – The IPSec sender can encrypt packets before transmitting them across a network.
2. Data Integrity – The receiver can authenticate packets sent by the IPSec sender to ensure that the data has not been altered during transmission.
3. Data Origin Authentication – The IPSec receiver can authenticate the source of the IPSec packets sent. This service is dependent upon the data integrity service.
4. Anti-Replay – The IPSec receiver can detect and reject replayed packet.
In Windows 2000, you have two options for IPSec implementation, Transport Mode, and L2TP Tunnel Mode. Transport mode is designed for securing communication, between nodes on an internal network. L2TP Tunnel Mode is designed for securing communication’s between two networks.
