Linksys NWR04B manual Router’s Ports, Internet, Ports 4, 3, Power

Network Everywhere® Series

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

Since the Router has firewall security (NAT), only the Router’s Internet IP address can be seen from the Internet.

However, even the Internet IP address can be blocked, so that the Router and network seem invisible to the Internet—This is shown in the Filters section in “Chapter 6: The Routers Web-Based Utility”.

Dynamic IP Addresses

A dynamic IP address is automatically assigned to a device on the network, such as PCs and print servers. These IP addresses are called “dynamic” because they are only temporarily assigned to the PC or device. After a certain time period, they expire and may change. If a PC logs on to the network (or the Internet) and its dynamic IP address has expired, the DHCP server will assign it a new dynamic IP address.

For DSL users, many ISPs may require you to log on with a user name and password to gain access to the Internet. This is called “Point to Point Protocol over Ethernet” or PPPoE. PPPoE is similar to a dial-up connection but does not have a phone number to dial into, and PPPoE is a dedicated high-speed con- nection. PPPoE also will provide the Router with a dynamic IP address to establish a connection to the Internet.

DHCP (Dynamic Host Configuration Protocol) Servers

DHCP frees you from having to assign IP addresses manually every time a new user is added to your network. PCs and other network devices using dynamic IP addressing are assigned a new IP address by a DHCP server. The PC or net- work device obtaining an IP address is called the DHCP client. The Router’s Internet port is, by default, set as a DHCP client.

DHCP servers can either be a designated PC on the network or another network device, such as the Router. By default, a DHCP server is enabled on your Router’s LAN ports. If you already have a DHCP server running on your net- work, you must disable one of the two DHCP servers. If you run more than one DHCP server on your network, you will experience network errors, such as conflicting IP addresses. To disable the Router’s DHCP function, see the DHCP section in Chapter 6: The Router’s Web-Based Utility.

Note: Even if you assign a static IP address to a PC, other PCs can still use DHCP’s dynamic IP addressing, as long as the static IP is not within the DHCP range of the LAN IP Address.

If the Router’s DHCP function fails to provide a dynamic IP address for any reason, please refer to Appendix A: Troubleshooting.

Wireless Cable/DSL Router

The Router’s Ports

Figure 1-1

The Router’s rear panel (as shown in Figure 1-1) is where all of its connections are made.

Internet	The Internet Port is where you will connect your cable or
	DSL modem with an Ethernet cable. Your modem con-
	nection will not work from any other port.
Ports 4, 3, 2	These four LAN (Local Area Network) ports are where
	you will connect networked devices, such as PCs, print
	servers, and any other Ethernet devices you want to put
	on your network. If Port 1 is being used, the Uplink Port
	will not work.

Port 1/Uplink Port The Uplink Port is where you can expand your network by connecting to a switch. Uplinking to a switch is done by simply running a cable from the Uplink Port to the other device. The Uplink Port is shared with Port 1. Pushing in the Uplink button allows this port to be used as the Uplink port. If the Uplink button is not pushed in, this port functions the same as Ports 4, 3, and 2.

Power	The Power Port is where you will connect the included
	AC Power adapter.

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