VPN Overview

What is a VPN? What is an IP VPN? VPNs vs. Private Data Networks, Internet VPNs, Intranet VPNs, Remote access VPNs, Site to site VPNs, VPN benefits and disadvantages.

VPN Tunnelling

VPN components, VPN tunnels, tunnel sources, tunnel end points, hardware based VPNs, Firewall based VPNs, software based VPNs, tunnelling topologies, tunnelling protocols, which tunnelling protocol should you use?, requirements of tunnels.

VPN Security Components

Critical VPN security requirements, Encryption and authentication, Diffie Hellman, DES, 3DES, RSA, PKI, Ca server types, pre shared keys versus certificates, Enrolling with a CA, RADIUS in VPNs.

PPP/PPTP

Encapsulation, operation, authentication. Exercise: Setting up PPPoE and analysing PPP packets.Overview, Components, How it works, control and data connections, GRE. Exercise: Building a PPTP VPN.

L2TP

Overview, components, how it works, security, packet authentication, L2TP/IPSec, L2TP/PPP, Layer 2 versus layer 3 tunnelling. Exercise: Implementing a L2TP tunnel

IPSec

AH, HMAC, ESP, transport and tunnel modes, Security Association, use of encryption and authentication algorithms, manual vs automated key exchange, NAT and other issues. Exercise: Implementing an IPSec VPN

VPN Issues and Architectures

VPN architectures: terminate VPN before/on/after/in parallel with firewall, resilience issues, VRRP, performance issues, MPLS, QoS and VPNs