Netopia 3300-ENT Series, Руководство пользователя для прошивки

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Virtual Private Networks (VPNs) 5-1
Chapter 5
Virtual Private Networks (VPNs)
The Netopia Firmware Version 8.7 offers IPsec, PPTP, and ATMP tunneling suppor t for Vir tual Private Networks
(VPN).
The following topics are covered in this chapter:
•
"Over view" on page 5-1
•
"About PPTP Tunnels" on page 5-4
•
"About IPsec Tunnels" on page 5-7
•
"About L2TP Tunnels" on page 5-8
•
"About GRE Tunnels" on page 5-11
•
"About ATMP Tunnels" on page 5-15
•
"Encr yption Suppor t" on page 5-17
• "ATMP/PPTP Default Profile" on page 5-18
• "VPN QuickView" on page 5-20
• "Dial-Up Networking for VPN" on page 5-21
• "Allowing VPNs through a Firewall" on page 5-25
• "Windows Networking Broadcasts" on page 5-32
Overview
When you make a long distance telephone call from your home to a relative far away, you are creating a private
network. You can hold a conversation, and exchange information about the happenings on opposite sides of the
state, or the continent, that you are mutually interested in. When your next door neighbor picks up the phone to
call her daughter at college, at the same time you are talking to your relatives, your calls don't overlap, but each
is separate and private. Neither house has a direct wire to the places they call. Both share the same lines on
the telephone poles (or underground) on the street.
These calls are vir tual private networks . Vir tual , because they appear to be direct connections between the
calling and answering par ties, even though they travel over the public wires and switches of the phone
company;
private , because neither pair of calling and answering par ties interacts with the other; and networks ,
because they exchange information.
Computers can do the same thing; it's called Vir tual Private Networks (VPNs). Equipped with a Netopia Router,
a single computer or private network (LAN) can establish a private connection with another computer or private
network over the public network (Internet).