Virtual Private Network (VPN)
■ Extends a private network across a public network, allowing users to send and receive data securely as if their devices were directly connected to the private network
■ Uses tunneling protocols to establish a secure connection over the public internet
Types of VPNs
■ Site-to-Site VPN
● Connects two offices or sites
● Provides a cost-effective alternative to dedicated lease lines
■ Client-to-Site VPN
● Connects a single remote user to a corporate network, enabling remote work or telecommuting
■ Clientless VPN
● Creates a secure remote access VPN tunnel using a web browser, without requiring software or hardware clients
Tunneling protocols (HTTPS Connection)
○ Secure Socket Layer (SSL)
■ Provides cryptography and reliability using the upper layers of the OSI model (Layers 5, 6, and 7)
■ Outdated and less secure
○ Transport Layer Security(TLS)
■ Provides secure web browsing over HTTPS
■ More updated than SSL
○ Both SSL and TLS use TCP
■ Can slow down connection due to more overhead
UDP Alternative:
■ Datagram Transport Layer Security (DTLS)
● UDP version of TLS
● Provides same level of security as TLS
● Operates faster due to less overhead inside UDP protocol
● An excellent choice for video streaming and voiceover IP over secure and encrypted tunnels
VPN Configuration for Site-to-Site and Client-to-Site
■ Full Tunnel
● Routes and encrypts all traffic through the VPN connection, making the remote user part of the headquarters network
■ Split Tunnel
● Divides traffic, routing and encrypting traffic bound for headquarters over the VPN while sending other traffic directly to the internet
● Offers better performance but may be less secure
■ Use full tunnel when connecting VPN over an untrusted network like wifi at a hotel or a coffee shop
Older VPN Protocols
■ Layer 2 Tunneling Protocol (L2TP)
● A very early VPN invented in the 80s and 90s
● Lacks security features like encryption by default
● Needs to be combined with an extra encryption layer for protection
■ Layer 2 Forwarding (L2F)
● Originally developed by Cisco
● Provides a tunneling protocol fir the P2P protocol (PPP)
● Lacks native security and encryption features
■ Point-to-Point Tunneling Protocol (PPTP)
● Supports dial-up networks
● Lacks native security features except when used with Microsoft Windows
Modern VPNs
■ IP Security (IPsec)
● Provides authentication and encryption of packets to create a secure communication path between two computers
Remember that
Tunneling protocols like SSL/TLS, L2TP, L2F, PPTP, and IPsec can be used to establish VPN connections
