1. Virtual Private Networks
Alexandra Altea Curti 5^AiS
a.s

2. What is a VPN? Virtual Private Network Private network Extended LAN
WAN

3. What do VPNs do?
Remote access
Individual users
Companies
Offices

4. Remote-access VPN Individual users Secure connection NAS
Client Software
Like if they were directly plugged into the network’s servers.

5. Site-to-site VPN Offices Secure connections Intranet-based
Extranet-based
Extends the company’s network in such a way that the computer resources from one location are available to employees at other locations.

6. Security Authentication Secrecy Integrity and authenticity protocols
Tunneling mechanism

7. Transmission mechanisms
Transport mode
Software
Encrypted data
Original header
Encryption and decryption guaranteed by software

8. Transmission mechanisms
Tunneling mode
Encapsulates encrypted data
New IP header
Readable only with decryption key

9. IPsec (IP security) Securing communications Encrypts every IP packet
Protocols:
Authentication Header (AH)
Encapsuling Security Payload (ESP)
Internet Key Exchange
Explain protocols fot mutual authentication!

10. Internet Key Exchange (IKE)
Mutual authentication and key-exchange
Peer-to-peer communication
SA (Security Association): Security policies defined for communication between two or more entities
Security associations are security policies defined
for communication between two or more entities;
the relationship between the entities is represented
by a key. The IKE protocol ensures security for SA
communication without the preconfiguration that
would otherwise be required.

11. Cryptography
Encrypted data
Long key
Secrecy

12. Proxy server VS VPN Proxy VPN Tunneling Own IP address
Fully encrypted traffic
High costs
Own IP address
Traffic not encrypted
Bypassed easily

13. VPNinja PPTP VPN service US and UK servers
Bypass corporate/government firewalls
Anonymous Internet access

14. Other VPN services Numerous countries Local WiFi
Mobile devices, PCs, tablets, computers
Apple, Windows, Android

15. Thank you for your attention

16. Network Access Server (NAS)
Media gateway/Remote Access Server (RAS)
VPN access
Authentication

17. Client Software VPN connection Incorporated or downloaded app
Cryptography for secure connection

18. Intranet site-to-site VPN
Offices in remote locations
Separated LANs
One single WAN
Connect each separate LAN into a single WAN.

19. Extranet site-to-site VPN
Partners, suppliers, clients (companies or individuals)
Connect LANs
Work together in a secure environment