Quiz Question

AvgITGeek

Hi everyone! I'm studying for the CCNA (will probably take the two exams) so I took a little 15 question CCNA quiz from www.learncisco.net and I have a question about why my answer is wrong. The site does not give explanations on why an answer is wrong so I thought I'd ask it here.

Here it is:

You are configuring PAT on your Cisco IOS router. Which command is used to identify the private IP addresses that can be translated?

a) access-list 1 permit 10.1.1.0 0.0.0.63

b) ip nat outside

c) ip nat pool NAT_POOL 203.0.113.3 203.0.113.6 prefix-length 29

d) ip nat inside

e) ip nat inside source list 1 interface fastethernet0/0 overload

I selected A as this is adding those internal addresses to an access-list which will then be set in the actual ip nat command.

The side is saying e is the correct answer. But why?

kaiju

It is "E" because "source list 1" refers to the allowed traffic in the acl that is to be translated. "E" is also the textbook method for configuring PAT.

AvgITGeek

I know that e is the textbook method for configuring PAT. The question is about identifying the internal addresses allowed to use PAT and isn't defining them in the access-list doing just that?

EDIT: OK. After re-reading your response and the question again I get it. Thanks!

clarson

well you need to know what is being asked.  in this case it is "configuring PAT".  

all these commands are used to configure PAT.  so which of these are different from the rest.  

so what to use to define which are different.  in this case how is "configuring PAT" different from "configuring NAT"

and in this case, the only command that is used to configure PAT and not NAT is the one with the "overload" keyword.

the rest of the commands aren't wrong in that they are used to configure PAT.  but, they are also used to configure other things too, such as NAT.  

and a) just defines an access list.  the access list doesn't define the private ip addresses until it is used in the "ip nat inside source list 1" command.

while this does test your skill with configuring NAT and PAT, it also tests how well you know how to take tests.

AvgITGeek

This one will be interesting for me for sure as this will be my first Cisco exam. I'm used to the Microsoft side of question asking.