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Chapter 11
Specify Your Network Settings
11. 8. Set up a VPN Connection
VPN (Virtual Private Network) is a private network established across the public network,
generally via the internet. However, the private network is a logical network without any
physical network lines, so it is called Virtual Private Network.
With the wide application of the internet, more and more data need to be shared through
the internet. Connecting the local network to the internet directly, though can allow the
data exchange, will cause the private data to be exposed to all the users on the internet.
The VPN (Virtual Private Network) technology is developed and used to establish the
private network through the public network, which can provide a secure communication
to a remote computer or remote network, and guarantee a secure data exchange. IPSec
is one of the major implementations of VPNs.
Establish an IPSec VPN tunnel to connect two LANs via
internet so that the hosts in different remote LANs are able to
communicate with each other as if they are in the same LAN.
For example
, I am the network administrator of a regional office,
I need to let my office staff to visit the headquarters’ servers and
resources, and vice versa. I know that the router in my office and
the device in headquarters both support IPSec VPN feature, so
I decide to set up a VPN connection with the headquarter office.
The following diagram is a typical VPN topology. Here Site A
refers to regional office’s network (local network). And Site B
refers to the headquarters’ network (remote network) which I
want to connect to.
Router 1
LAN: 192.168.1.1
WAN: 219.134.112.246
PC 1
Subnetmask: 255.255.255.0
WAN: 219.134.112.247
Router 2
PC 2
LAN: 192.168.2.1
Subnetmask: 255.255.255.0
Site A
Site B
1.
1. Make sure of the topology you want to build and record
site A (local network) and site B (remote network)’s LAN IP
and WAN IP.
2.
Configuration on site A (local network).
I want to:
How can
I do that?