VPN VIRTUAL PRIVATE NETWORK THEORY

VPN: Virtual Private Network theory

VPN: Virtual Private Network – Establishing connection between two private networks

(trusted Sites) over the internet (untrusted Sites) is called VPN.

Types of VPN:

          Site to Site VPN

          Remote Access VPN

Site to Site VPN: Connect branch office to Head office.

          Branch office users can use the resources such as email, files, printers, are located

in head office. Site to Site VPN user IPSEC to provided data security.

Remote Access VPN: Remote Access VPN provides secure access for remote users.

Remote users required VPN client software to connect & access the office resource

from the remote location or home.

Remote Access VPN Types:

Client based

 Clientless (Web VPN or SSL VPN)

Client based: User system must have VPN Client software (IPSEC Software) in his PC or

Laptop. Through that software remote users connect to the office.

IPSEC initiated by VPN Client.

Clientless: (Web VPN or SSL VPN): this method required only browsers. Browsers act as a

client. Instead of Ipsec here SSL (Secure Socket Layer) to connect to the secure gateway

and the access the resources from remote location.

SSLVPN Initiated via browser https://Address it will ask username and password. Cookies

Should enable.

Cisco any connect VPN client process using IPSEC and UDP.

VPN Client Process:

          Client Starts IKE Phase 1 – Pre-shared Key

          Client Propose IKE SA’s

          Server accept SA proposal

          Server initiate challenge (send Username and Password)

          Server configuration (DNS, Domain Name, IP)

          Group level authentication.