3Com 3C8S5007 - SuperStack II PathBuilder S500 Switch, Руководство пользователя

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5
C
ONFIGURING AND
M
ONITORING
V
IRTUAL
P
RIVATE
N
ETWORKS
This chapter describes virtual private networking and how to use a
PathBuilder switch with Enterprise OS software to configure and monitor
a virtual private network (VPN).
Remote Access
Alternatives
VPNs are a cost-effective alternative for providing remote access or
remote office connectivity to a central site.
Typically a company is required to use dedicated leased lines,
packet-switching services, and/or direct dialup connections to enable
remote users and remote offices to connect to a central site. A VPN
provides a less expensive method of providing this connectivity.
The internet service provider (ISP) is an important element in of a VPN. By
providing local access for any remote user or remote office, the ISPs
network replaces the leased lines, packet-switching services, and direct
dialup connections. Instead of directly managing remote access WAN
lines a company can outsource this responsibility to an ISP, resulting in
fewer WAN issues to track and potentially significant cost savings.
Using Tunnels To ensure security and multiprotocol support, a tunnel is created to the
central site. Tunneling allows you to encapsulate IP and non-IP packets, to
provide security using IPsec, and to obtain access to the central site
network through a firewall.
A tunnel can be set up in one of two ways:
■
From the ISP to the central site. This configuration is used to connect
individual remote users to a central site.
■
From a remote site to the central site. This configuration is used to
connect a remote office to a central site.