Cisco Systems RVS4000RF manual Networking and Security Basics, An Introduction to LANs

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Networking and Security Basics

This chapter describes networking and security basics. It includes these sections:

•An Introduction to LANs, page 9

•The Use of IP Addresses, page 10

•The Intrusion Prevention System (IPS), page 11

An Introduction to LANs

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 feature keeps your LAN remains private. The router protects your network by inspecting the first packet received through the Internet port before delivering it 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.

Cisco RVS4000 Security Router with VPN Administrator Guide 9