Chapter 6. Building IPsec VPNs
Overview of IPsec VPNs
An IPsec VPN is probably one of the most used network types today. Its benefits include the connectivity of branches, remote users, and partners near and far. The fact that this technology is so widely used makes it clear that the fundamental concepts, technologies, and terms must be understood.
So what is IPsec supposed to do? Simple really: IPsec is an IETF standard (RFC 2401–2412) that enables us to send private or confidential data over a public medium such as the Internet securely. To do this, IPsec must provide the following:
- Confidentiality with data encryption
- Integrity checks on the data transmitted with a checksum
- Authentication of the peer using something like a preshared or agreed-upon ...