Syngress - Eleventh Hour Network+ Exam N10-004 Study Guide (11 ...

96 CHAPTER 6 TCP/IP and Routing
■ 10.0.0.0/8 Class A network address with the host ID range of 10.0.0.1
through 10.255.255.254.
■ 172.16.0.0/12 Class B network address with a host ID range of 172.16.0.1
through 172.31.255.254.
■ 192.168.0.0/16 Class C network address with the host ID range of
192.168.0.1 through 192.168.255.254.
Another use of private addressing is called automatic private IP addressing (APIPA).
If a computer running Windows 98 or later is configured to obtain its address
automatically from a dynamic host configuration protocol (DHCP) server and it
cannot locate a DHCP server, it will configure itself using APIPA. The computer
randomly selects an address from the 169.254.0.0/16 address range and then
checks the network for uniqueness. If the address is unique, it will use that address
until it can reach a DHCP server. If the address is not unique, it will randomly
select another address from that range.
EXAM WARNING
You must know the private address ranges as well as the APIPA IP address range for the
Network+ exam. Also, do not forget the reserved loopback Class A address of 127.0.0.0.
Considerations
The private address blocks can be used in any network at any time. However,
devices using these addresses will not be able to communicate with other hosts
on the Internet without some kind of address translation. Some benefits of using
private addresses are as follows:
■
■
■
■
Number of addresses There are plenty of addresses for most internal
networking needs.
Security Private addresses are not routable on the Internet. The translation
from private to public addresses further obscures internal network
information.
Renumbering If using NAT, no readdressing of privately addressed networks
is necessary to access public networks.
Network design Treating private addresses as public addresses when
allocating ensures that efficiency and design are maximized.
STATIC AND DYNAMIC ASSIGNMENTS
■ Static addressing Addressing configured by going to the physical location of
a node or connecting through remote administration to configure a usable
IP address.
■ Dynamic addressing Addressing configured by a central server, which
allocates and tracks the usage of IP addresses in the network.