Linksys BEFSR41 v2 EN - Manual (Page 11)

EtherFast Cable/DSL Routers
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Instant Broadband Series
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Your Router’s firewall (NAT) protects your network of PCs with security so
users on the public, Internet side cannot “see” your PCs. This is how your
internal LAN, or network, remains private.
Remember that your Router’s ports connect to two sides: your 10/100 LAN
port(s) and the Internet WAN port. The LAN port(s) transmit data at 10Mbps
or 100 Mbps, whereas the broadband port, or WAN port, transmits data at 10
Mbps, because 10Mbps is currently the maximum speed for cable and DSL
service.
IP Addressing: A Quick Lesson
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. Since the Internet
is simply one huge global network, every
PC that logs on to the Internet also requires
an IP address.
There are two ways of assigning an IP
address to your network devices.
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 insures that the device assigned it will always have that
same IP address. Static IP addresses are commonly used with network devices
such as server PCs or print servers.
If you use your Router to share your cable or DSL Internet connection, contact
your ISP to find out if they have assigned a static IP address to your account.
If so, you will need that static IP address when configuring your Router.
Connecting the Cable/DSL Router to
Your Network
Overview
Unlike a hub or a switch, the Cable/DSL Router’s setup consists of more than
simply plugging hardware together. Since the Router acts as a DHCP server,
you will have to set some values for the Router and also configure your net-
worked PCs to accept the IP addresses that the Router assigns them.
You will need the following data from your ISP (Internet Service Provider) to
install the Cable/DSL Router:
• Your broadband-configured PCs’ Computer Name and Workgroup Name
• Your broadband-configured PCs’ fixed
Internet IP Address
• Your Subnet Mask
• Your Default Gateway
• Your Primary DNS Server IP address(es)
The installation technician from your ISP should have left this information with
you after installating your broadband connection. If not, you can call your ISP
to request the data.
Once you have the above values, you can begin the Installation and Setup of
your EtherFast Cable/DSL Router.
LANs and WANs
Simply put, a router is a network device that connects two networks together.
In this instance, your EtherFast Cable/DSL Router connects your Local Area
Network (LAN), or the group of PCs in your home or office, to the Wide Area
Network (WAN), that is, the Internet. Your Router processes and regulates the
data that travels between these two networks.
Think of your Router as a network device with two sides: the first side is made
up of your private Local Area Network (LAN) of PCs, which this User Guide
sometimes calls the “internal LAN.” The other, public side is the Internet, or
the Wide Area Network (WAN), outside of your home or office.
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Only if applicable
Since your Router is a device that con-
nects two networks, it needs two IP
addresses - one for the LAN side, and
one for the WAN side. In this User
Guide, you’ll see references to the
“WAN IP address” and the “LAN IP
address.”
Since the Router has firewall security
(NAT), the only IP address that can be
seen from the Internet for your net-
work is the Router’s WAN IP address.
However, even this WAN IP address
for the Router can be blocked, so that
your Router and network seem invisi-
ble to the Internet - see the Blocking
WAN Requests description under IP
Filtering.