User`s guide

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The first stage in establishing a secure link between two endpoints on an IP network is for
those two points to securely exchange a little information about each other. This enables
the endpoint responding to the request to decide whether it wishes to enter a secure
dialogue with the endpoint requesting it. To achieve this, the two endpoints commonly
identify themselves and verify the identity of the other party. They must do this in a secure
manner so that the process cannot be “listened in to” by any third party. The IKE protocol is
used to perform this “checking” and if everything matches up it creates a Security
Association (SA) between the two endpoints, normally one for data being sent TO the
remote end and one for data being received FROM it.