Chapter 2: Networking And Security Basics; An Introduction To Lans; The Use Of Ip Addresses - Cisco QuickVPN - PC Administration Manual

Networking and Security Basics

An Introduction to LANs

The Use of IP Addresses

Cisco RVS4000 4-Port Gigabit Security Router with VPN Administration Guide
This chapter describes networking and security basics. It includes the following
sections:
•
An Introduction to LANs, page 7
•
The Use of IP Addresses, page 7
•
The Intrusion Prevention System (IPS), page 9
A router is a network device that connects two networks together.
The router connects your local area network (LAN), or the group of PCs in your
home or office, to the Internet. The router processes and regulates the data that
travels between these two networks.
The router's Network Address Translation (NAT) technology protects your network
of PCs so users on the Internet cannot "see" your PCs. This is how your LAN
remains private. The router protects your network by inspecting the first packet
coming in through the Internet port before delivery to the final destination on one
of the Ethernet ports. The router inspects Internet port services like the web
server, ftp server, or other Internet applications, and, if allowed, it will forward the
packet to the appropriate PC on the LAN side.
IP stands for Internet Protocol. Every device in an IP-based network, including PCs,
print servers, and routers, requires an IP address to identify its location, or
address, on the network. This applies to both the Internet and LAN connections.
There are two ways of assigning IP addresses to your network devices.
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