User's Manual

SPEEDLAN 8500 Series Installation and Operation User Guide
7-8 Setting Up the IP Addresses (IP Host Setup)
Note: If the network is managed by a Simple Network Management Protocol for local or
Internet access, each IDU must contain a unique IP Address. This is a benefit of static or
dynamic addressing.
How does a network administrator assign an IP address?
IP addresses are supplied by the network administrator, the ISP, or hosting company.
The two types of IP addressing—manual (static) and automatic (dynamic) addressing—are described
below.
• Manual (static) Addressing
Each device connected to the Internet must have its own unique IP address. Also, if a
computer is being used as a server, you will assign it a permanent IP address. This enables
other computers to connect to it. Static addressing is also beneficial to users that need to
maintain a "constant" connection to the Internet. This will enable users to easily access the IP
address.
• Automatic (dynamic) Addressing
A DHCP (Dynamic Host Configuration Protocol) server assigns the IP address to each
computer as the computer connects to the network. If a computer moves to a new network
(i.e., great for temporary employees or mobile users), it must be assigned a new IP address
for that network. DHCP can be used to manage these assignments automatically. DHCP is
described in further detail below.
What is DHCP?
Dynamic Host Configuration Protocol (DHCP) allows network administrators to assign dynamic IP
addresses for the period of time needed to connect to the Internet. Think of DHCP as leasing an
apartment. A prospective tenant may not need to live in an apartment for two years, maybe just a
year. Therefore, the tenant will only sign a one-year lease agreement. For example, each time a
computer is set up to connect to the Internet, the network administrator uses DHCP to automatically
assign the computer a unique IP address. That computer will give up its IP address when it is no
longer needed (when the lease has ended) allowing new a computer (or a new tenant) on the same
network to use it. This benefits educational and corporate settings where users often log on to
different computers. In this case more IP addresses outnumber computers because you can quickly
reconfigure the network if needed from a centralized location.