From getting started to being proficient in hacker Linux, haima won't be able to handle VPN servers in 3 minutes

agenda:
. VPN introduction
. VPN working principle
. VPN data transmission protocol
. VPN Server construction
case: Company X has a long distance between departments, and the company's network cannot accommodate a LAN, to ensure secure transmission and easy management of information in each LAN, what are your best methods as system administrators?
solution: 1. Set up a dedicated line between each LAN and establish a point-to-point connection to form a wan.
2. Establish a Virtual Private Network Using VPN technology.
Virtual Private Network VPN
VPN is short for virtual private network. It is a private network built on a public network. When you use a private network, it feels like a network connected by a VPC. Its transmission channel is private and independent, however, the actual data is transmitted through the public network and thus becomes a virtual private network.
Key Technologies of VPN
Key Technologies for VPN implementation
. security Tunnel Technology
. encryption technology
. authentication

VPN data transmission protocol
PPTP
. IP-based Internet
. No Header Compression
. No tunneling Authentication
. Use PPP Encryption
L2TP
. Based on a variety of WAN connections, such as frame relay, IP, X.25
. Header Compression
. Tunnel Authentication
. Use IPsec Encryption
Client ----- PPTP/L2TP ------ Server
VPN security protocol (1)
PPTP ---- Point to Point tunnel protocal (point-to-point tunnel protocol)
For data communication over the Internet, data streams need to be encapsulated and encrypted. PPTP can implement these two functions to implement multi-function communication over the Internet.
VPN security protocol (II)
L2TP ---- Layer2 Tunneling Protocol (Layer 2 tunnel protocol)
PPTP and L2TP are very similar, because one part of L2TP adopts the PPTP protocol. both Protocols allow the customer to establish a tunnel through the network. L2TP also supports channel authentication.
Benefits of Using VPN
(1) reduce costs.
(2) enhanced security.
(3) network protocol support.
(4) ip address security.

Updating ........