User's Manual

User Manual
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5.2 VPN
VPN is intended to establish a private network on the public network for
encrypted communication. A VPN router enables remote access by encrypting
data packets and converting the destination address of data packets. VPN can
be realized by a server, hardware, or software. Compared with the traditional
DDN private line or frame relay, VPN provides a more secure and convenient
remote access solution.
A common VPN application scenario: An employee on a business trip wants
to access to the enterprise's intranet. The employee connects to enterprise's
VPN server and then accesses to enterprise's intranet through the VPN server.
Communication data between the VPN server and the client is encrypted and
can be regarded as being transmitted on a dedicated data network. This
ensures data security.
5.2.1 IPsec
IPsec is a group of open network security protocols developed by IETF. At the IP
layer, data source authentication, data encryption, data integrity, and
anti-replay functions are used to ensure the security of data transmission
between communication parties on the Internet. This reduces the risk of
leakage and eavesdropping, ensures the integrity and confidentiality of data,
and the security of service transmission for users.
Scenario: Data is transmitted between the subnet (192.168.1.0/24) of
headquarters A and the subnet (172.16.1.0/24) of customer branch B through
router A and router B. The transmission channels between router A and router B