27 introducing VPN solutions kho tài liệu bách khoa

VPN ModelsVPN services can be offered based on two major models: • Overlay VPNs , in which the service provider provides virtual point-to-point links between customer sites • Peer-to-pe

BSCI v3.0—2-1

Introducing VPN Solutions

VPN Taxonomy

VPN Models

VPN services can be offered based on two major

models:

• Overlay VPNs , in which the service provider provides virtual point-to-point links between customer sites

• Peer-to-peer VPNs , in which the service provider participates

in the customer routing

What Is a VPN?

Virtual: Information within a private network is transported over a public network.

Private: The traffic is encrypted to keep the data confidential.

Benefits of VPN

 Cost

Site-to-Site VPNs

Site-to-site VPN: extension of classic WAN

Remote-Access VPNs

Remote-access VPN: evolution of dial-in networks and ISDN

Generic Routing Encapsulation

OSI Layer 3 tunneling protocol:

protocol as payload (e.g., IP, IPX, AppleTalk)

Default GRE Characteristics

of GRE

integrity assurance)

GRE header)

GRE Configuration Example