ZyXEL Communications Corporation VSG1435B101 Manuel D’Utilisation

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VSG1435-B101 Series User’s Guide
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IPSec
21.1  Overview
A virtual private network (VPN) provides secure communications between sites 
without the expense of leased site-to-site lines. A secure VPN is a combination of 
tunneling, encryption, authentication, access control and auditing. It is used to 
transport traffic over the Internet or any insecure network that uses TCP/IP for 
communication.
Internet Protocol Security (IPSec) is a standards-based VPN that offers flexible 
solutions for secure data communications across a public network like the 
Internet. IPSec is built around a number of standardized cryptographic techniques 
to provide confidentiality, data integrity and authentication at the IP layer. The 
following figure is an example of an IPSec VPN tunnel.
Figure 114   VPN: Example
21.1.1  What You Can Do in this Chapter
• Use  the  Status screen to display and manage the current active VPN 
connections (
Section 21.2 on page 251
).
• Use  the  Settings screen to view the configured IPSec policies and add, edit or 
remove a policy (
Section 21.3 on page 252
).
VPN Tunnel
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