Foundation Summary 355
Foundation Summary
The Foundation Summary is a collection of information that provides a convenient review of
many key concepts in this chapter. For those of you already comfortable with the topics in this
chapter, this summary could help you recall a few details. For those of you who just read this
chapter, this review should help solidify some key facts. For any of you doing your final
preparation before the exam, these tables and figures will hopefully be a convenient way to
review the day before the exam.
The addresses used for NAT translation can be summed up in four categories:
·
Inside Local--IP addresses that are unique to the host inside the network, but not globally
significant. They are generally allocated from RFC 1918 or randomly picked.
·
Inside Global--IP addresses that are assigned by the IANA or service provider. They are
legitimate in the global address space or Internet. The Inside Local addresses are
translated to the Inside Global address for Internet use.
·
Outside Local--IP addresses of a host on an outside network that is presented to the
inside network and that is legitimate to the local network. These addresses do not have to
be globally significant. They are generally selected from RFC 1918 or randomly picked.
·
Outside Global--IP addresses that are globally routable on the Internet space.
To make the thought process easier, consider the following definitions::
·
Inside--Addresses that are inside my network
·
Outside--Addresses that are outside my network
·
Local--Addresses that are legitimate inside my network
·
Global--Addresses that are legitimate outside my network
Table 11-3
Private Address Space Ranges
Address Class
Range
Number of Networks
A
10.0.0.0 1
B
172.16.0.0172.31.0.0
16
C
192.168.0.0192.168.255.0
255