Avocent Cyclades-PR4000 installation manual Virtual Private Network Configuration

Cyclades-PR4000

CHAPTER 16 VIRTUAL PRIVATE NETWORK CONFIGURATION

The Virtual Private Network utility can be used on any link using IP routing. It is used to provide greater security between two or more networks connected through a public communications network. The basic concepts are presented in Figure 14.1. An IP datagram is sent by a device on the LAN. The message arrives at the router. The router has two tables. One with all the IP addresses contained in the Local Security Network and another with all the IP addresses in the Remote Security Networks. If the source IP address is contained in the Local Security Network list and the destination IP address is contained in the Remote Security Network list, the message is encrypted and encapsulated. The only destination address is that for the remote gateway (defined in the Remote Security Network list). Upon arrival at the remote gateway, the packet is unwrapped and sent to its destination.

PC	Message
		Local
IP Datagram		Gateway
sent by user

Message PC

Remote

Gateway

Header	PR3000 Message
Source IP Address
Destination IP Address
IP Options and Data	Public

Message

PR4000

Header

Source IP Address

Destination IP Address

IP Options and Data

	As sent by	Network
	local Gateway
	Header with destination:
Conversion	remote security gateway
	IP Address
performed by Router
with Cyclades’ VPN	Encrypted IP Datagram

As received by remote Gateway

Header with destination: remote security gateway IP Address

Encrypted IP Datagram

FIGURE 14.1 CONVERSION PERFORMED BY CYCLADES’ VIRTUAL PRIVATE NETWORK UTILITY

Chapter 16 - Virtual Private Network Configuration 142