Cisco Systems WRV54G 用户手册

4

Chapter 2: Planning your Wireless Network

Simply put, a router is a network device that connects two networks together. 

In this instance, 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 NAT feature protects your network of PCs so users on the public, Internet side cannot “see” your 
PCs.  This is how your network remains private. The Router protects your network by inspecting every packet 
coming in through the Internet port before delivery to the appropriate PC on your network. 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.

Remember that the Router’s ports connect to two sides. The LAN ports connect to the LAN, and the Internet port 
connects to the Internet.  The LAN and Internet ports transmit data at 10/100Mbps.

What’s an IP Address?

IP stands for Internet Protocol. Every device on 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 an IP address to your network devices. You can assign static 
IP addresses or use the Router to assign IP addresses dynamically.

Static IP Addresses  

A static IP address is a fixed IP address that you assign manually to a PC or other device on the network.  Since a 
static IP address remains valid until you disable it, static IP addressing ensures that the device assigned it will 
always have that same IP address until you change it.  Static IP addresses must be unique and are commonly 
used with network devices such as server PCs or print servers.

 

NOTE: Since the Router is a device that connects two 
networks, it needs two IP addresses—one for the LAN, 
and one for the Internet.  In this User Guide, you’ll see 
references to the “Internet IP address” and the “LAN IP 
address.”

Since the Router uses NAT technology, the only IP 
address that can be seen from the Internet for your 
network is the Router’s Internet IP address. However, 
even this Internet IP address can be blocked, so that the 
Router and network seem invisible to the Internet—see 
the Block WAN Requests description under Filters in 
“Chapter 7: The Router’s Web-based Utility.”