Cyclades-PR2000
CHAPTER 14 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 |
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IP Datagram | Gateway | |
sent by user |
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Message PC
Remote
Gateway
Header | PR3000 | Message |
Source IP Address |
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Destination IP Address |
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IP Options and Data |
| Public |
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Message
PR4000
Header
Source IP Address
Destination IP Address
IP Options and Data
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| As sent by | Network |
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| local Gateway |
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| Header with destination: |
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Conversion | remote security gateway |
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IP Address |
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performed by Router |
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with Cyclades’ VPN | Encrypted IP Datagram |
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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 14 - Virtual Private Network Configuration | 115 |
