1. Virtual Private Network Benefits Classification Tunneling technique, PPTP, L2TP, IPSec Encryption Technology Key Management Technology Authentication Settings

2. Virtual Private Network Logical Solution For Remote Access Secure Communications Tailored To Individuals Enhancing Productivity Increase Flexibility Reduce Costs of Communications

3. Classification based on protocols PPTP L2TP PPTP protocol and L2TP protocol are in the second layer of OSI model, so they are also called layer second tunneling protocol. IPSec IPSec is layer third tunneling protocol, which is the most common protocol.

4. Classification based on service applications Access VPN Client-initiated VPN connection NAS-initiated VPN connection Intranet VPN An intranet VPN interconnects distributed internal points of an enterprise through public networks. Extranet VPN An extranet VPN uses a VPN to extend an enterprise network to suppliers, partners, and clients.

5. Classification based on devices Switch VPN Mainly applied in VPN internet, which has fewer users. Router VPN Firewall VPN The firewall VPN is the most common kind of VPN type.

6. Classification based on principles Overlapping VPN Overlapping VPN needs users themselves to establish VPN link between nodes. Peer-to-peer VPN Peer-to-peer VPN tunnels are established by network operators in backbone network.

7. Tunneling technology helped achieve VPN Three layers: First: link layer and the network layer Second: tunnel PPP connections (as PPTP, L2TP ) Third: IPinIP (IPSec)

8. PPTP (Point to Point Tunneling Protocol ) Remote users can access corporate networks Dial into a local ISP Via a secure link to the Internet through systems that are equipped with Point to Point Protocol

9. L2TP :similar to PPTP protocol, but exist differences IP networks tunnel numbers Providing functions(header compression, tunnel authentication ) drafted by different companies

10. IPSec (InternetProtocolSecurity ) End-to-end protection

11. Two types Symmetric key Cryptography The encryption and decryption keys are the same. Data Encryption Standard(DES) Triple DES International Data Encryption Algorithm (IDEA) Blowfish

12. Asymmetric key Cryptography The encryption key is published for someone to use and encrypt messages. However, only the receiving party has access to the decryption key. RSA Diffie-Hellman

13. The computing speed of symmetric-key schemes is quite faster than the computing speed of public-key encryption. DES and Triple DES are more widely used in VPN system.

14. Key management Key exchange Key storage Key use Symmetric keys Asymmetric keys

15. Challenges of key management Complex management Security issues Data availability Governance

16. Authentication of VPN Computer level-Authentication User level- Authentication

17. CISCO ANYCONNETCT SETTINGS GUIDE

18. Step1 Launch the Anyconnect application

19. Step2 A username and password

20. Step3 check the status of the VPN connection