Linksys WRVS4400N - Manual (Page 14)

6 Chapter 2: Networking and Security Basics
The Use of IP Addresses
Wireless-N Gigabit Security Router with VPN
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 are commonly used with dedicated
network devices such as server PCs or print servers. Since a user’s PC is moving around in a network and is
being powered on or off, it does not require a dedicated IP address that could be a precious resource in your
network.
If you use the 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 the
Router. You can get the information from your ISP.
A dynamic IP address is automatically assigned to a device on the network. This IP address is called dynamic
because it is only temporarily assigned to the PC or other device. After a certain time period, it expires and may
change. If a PC logs onto the network (or the Internet) and its dynamic IP address has expired, the DHCP server
will assign it a new dynamic IP address. Most ISPs use dynamic IP addresses for their customers. By default, the
Router’s Internet Connection Type is Obtain an IP automatically (DHCP).
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 a dedicated, high-speed connection type called Point-to-Point Protocol over Ethernet (PPPoE).
PPPoE is similar to a dial-up connection, which establishes a PPP session with an ISP server through the DSL
connection. The server will also provide the Router with a dynamic IP address to establish a connection to the
Internet.
A DHCP server can either be located on a designated PC on the network or another network device, such as the
Router. The PC or network device obtaining an IP address is called the DHCP client. DHCP frees you from having to
assign IP addresses manually every time a new user is added to your network. For this Wireless-N Router, a DHCP
client is running on a WAN port for most configurations. A DHCP server is running on the LAN side to provide
services.
By default, a DHCP server is enabled on the Router. If you already have a DHCP server running on your network,
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 DHCP on the Router, refer to the Basic
Setup section in “Chapter 6: Setting Up and Configuring the Router.”
Dynamic IP address: a temporary IP
address assigned by a DHCP server.
Static IP address: a fixed address
assigned to a computer or device that
is connected to a network.
DHCP (Dynamic Host Configuration
Protocol): a protocol that lets one
device on a local network, known as a
DHCP server, assign temporary IP
addresses to the other network
devices, typically computers.