TCP/IP Protocol Suite 1 Upon completion you will be able to: Virtual Private Networks and Network Address Translation Understand the difference between.

TCP/IP Protocol Suite 1

Upon completion you will be able to:

Virtual Private Networks andVirtual Private Networks andNetwork Address Translation Network Address Translation

• Understand the difference between an internet and an extranet• Understand private, hybrid, and virtual private networks• Understand how VPN can guarantee privacy• Understand the mechanism of NAT

Objectives


26.1 PRIVATE NETWORKS

A private network is designed to be used only inside an organization. It A private network is designed to be used only inside an organization. It allows access to shared resources and, at the same time, provides allows access to shared resources and, at the same time, provides privacy.privacy.

The topics discussed in this section include:The topics discussed in this section include:

Intranet Intranet Extranet Extranet Addressing Addressing


Table 26.1 Table 26.1 Addresses for private networksAddresses for private networks


26.2 VIRTUAL PRIVATE NETWORKS (VPN)

Virtual private network (VPN) is a technology for large organizations Virtual private network (VPN) is a technology for large organizations that use the global Internet for both intra- and interorganization that use the global Internet for both intra- and interorganization communication, but require privacy in their intraorganization communication, but require privacy in their intraorganization communication. communication.


Achieving Privacy Achieving Privacy VPN Technology VPN Technology


Figure 26.1 Private network


Figure 26.2 Hybrid network


Figure 26.3 Virtual private network


Virtual private network

A typical VPN might have a main LAN at the corporate headquarters of a company, other LANs at remote offices or facilities and individual users connecting from out in the field.

http://www.howstuffworks.com/lan-switch.htm


VPN Types:

•Remote Access VPN

•Intranet VPN

•Extranet VPN


Remote-Access VPN Remote-Access VPN also called a virtual

private dial-up network (VPDN), is a user-to-LAN connection used by a company that has employees who need to connect to the private network from various remote locations.

Intranet-based - If a company has one or more remote locations that they wish to join in a single private network, they can create an intranet VPN to connect LAN to LAN.

Extranet-based - When a company has a close relationship with another company (for example, a partner, supplier or customer), they can build an extranet VPN that connects LAN to LAN, and that allows all of the various companies to work in a shared environment.


Figure 26.4 Tunneling

tunneling is the process of placing an entire packet within another packet and sending it over a network. You can place a packet that uses a protocol not supported on the Internet (such as NetBeui) inside an IP packet and send it safely over the Internet. Or you could put a packet that uses a private (non-routable) IP address inside a packet that uses a globally unique IP address to extend a private network over the Internet.

http://www.howstuffworks.com/web-server4.htm


Figure 26.5 Addressing in a VPN


26.3 NETWORK ADDRESS TRANSLATION (NAT)

Network address translation (NAT) allows a site to use a set of private Network address translation (NAT) allows a site to use a set of private addresses for internal communication and a set of global Internet addresses for internal communication and a set of global Internet addresses for communication with another site. The site must have only addresses for communication with another site. The site must have only one single connection to the global Internet through a router that runs one single connection to the global Internet through a router that runs NAT software.NAT software.


Address Translation Address Translation Translation Table Translation Table NAT and ISP NAT and ISP


Figure 26.6 NAT


Figure 26.7 Address translation


Figure 26.8 Translation


Table 26.2 Table 26.2 Five-column translation tableFive-column translation table


Figure 26.9 An ISP and NAT

TCP/IP Protocol Suite 1 Upon completion you will be able to: Virtual Private Networks and Network Address Translation Understand the difference between.

Documents

tcpip protocol suite

virtual private network

single private network

hybrid network slide

virtual private dial

privacy vpn technology

vpn types

typical vpn