ZyXEL Communications SBG5500-A, User Manual

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SBG5500 Series User’s Guide
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C
HAPTER
10
VPN
10.1 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.
10.2 What You Can Do in this Chapter
• Use the VPN Status screen to look at the VPN tunnels currently established in the SBG ( Section 10.4 on
page 162 ).
• Use the IPsec VPN screen to display and manage active IPsec VPN connections ( Section 10.5 on
page 163 ).
• Use the PPTP VPN screen to configure the PPTP VPN settings in the SBG( Section 10.6 on page 176 ).
• Use the L2TP VPN screen to configure the SBG’s L2TP VPN settings( Section 10.7 on page 179 ).
• Use the L2TP Client Status screen to view connection details for L2TP clients ( Section 10.8 on page
185 ).
10.3 What You Need to Know
IPsec VPN
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 provides one perspective of a VPN tunnel.