Answers to the Chapter 11 Q&A Section 437
15
Is PAT a subset of NAT? Defend your answer.
Pat is a subset of NAT within the 700 IOS code. The 700 does only PAT and does not have
the flexibility that the NAT implementation the Enterprise IOS code has. In general, PAT
really is a superset of NAT since PAT allows for the translation of the port number, as well
as the address. But, given the definitions of PAT and NAT used in this context, PAT is a
subset of the functionality that the Enterprise IOS offers.
Answers to the Chapter 11 Q&A Section
1
What are the benefits of NAT?
The benefits include conservation, overlap dysfunction, flexibility, and the elimination of
renumbering.
2
The Outside Global address is converted to which NAT address class?
It is converted to an Outside Local address.
3
What are the disadvantages of NAT?
The disadvantages include increased latency, lesser accountability, and nonfunctionality
with some applications
4
Using simple NAT translation, what TCP header information is altered?
The source IP address and the subnet mask are altered.
5
What private address space is available from RFC 1918?
6
What does it mean when a NAT translation is overloaded?
When a NAT translation is overloaded, the same IP address is used over and over, and the
tracking is done by using the source port number in addition to the source IP address.
7
Which commands would you use for an overloaded NAT translation using a defined pool
of addresses called transpool for outbound traffic?
ip nat inside source list 1 pool transpool overload
8
What TCP header information is altered using NAT overload?
The source IP address, the subnet mask, and the source port number are altered.
Address Class
Range
Number of Classful 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