Linksys SPA2102-NA User Manual page 14

Phone Adapter with Router
If you use the Phone Adapter 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
Phone Adapter. You can get the information from your ISP.
A dynamic IP address is automatically assigned to a device on the network. These IP addresses are called
dynamic because they are only temporarily assigned to the PC or other device. After a certain time period, they
expire 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.
A DHCP server can either be a designated PC on the network or another network device, such as the Phone
Adapter. By default, the Phone Adapter's Internet Connection Type is DHCP (obtain an IP address automatically).
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 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, but PPPoE does not dial a phone number when establishing a
connection. It also will provide the Phone Adapter with a dynamic IP address to establish a connection to the
Internet.
By default, a DHCP server (on the LAN side) is enabled on the Phone Adapter. 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
Phone Adapter, see the Router - LAN Setup section in "Chapter 5: Using the Web-based Utility."
6
dynamic ip address: a temporary IP
address assigned by a DHCP server.
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.
Chapter 2: Networking Basics
The Use of IP Addresses