User's Manual

SPEEDLAN 9000 Series Installation and Operation User Guide Version 3.03
Basics of IP Addressing 9-7
means that Blocks A, B, C, and D are all part of Long Street, which is also known as the
network in this example. The mailman would organize the letters (or IP addresses for
network equipment) by creating four piles (one for each block, or subnet). As soon as
the mailman picks up pile A in his hand, he knows which block to turn on. This same
reasoning applies to piles B, C, and D as well. Router D knows exactly which subnet to
transfer (or turn) the packets to by reading its IP and subnet mask address. Note that
each subnet on this network is 255.255.255.192. Why is 192 the last octet in the
subnet mask and not 64? The last octet, 192, is the mask that allows 64 "houses" to
know that the mailman (or router) is coming in advance. The "houses" will know it's
mailman "Jim" by looking at the IP number.
Note: If the network is managed by a Simple Network Management Protocol for
local or Internet access, each interface 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 - Is ’Manually Configure’ option on
Interfaces Parameters page of 9000 Configuator
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 - Is ’Use DHCP’ option on Interface
Parameters page of 9000 Configurator.
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.