CISCO CCNA Exam – Q246

What are two benefits of using NAT? (Choose two.)

A. NAT facilitates end-to-end communication when IPsec is enabled.
B. NAT eliminates the need to re-address all hosts that require external access.
C. NAT conserves addresses through host MAC-level multiplexing.
D. Dynamic NAT facilitates connections from the outside of the network.
E. NAT accelerates the routing process because no modifications are made on the packets.
F. NAT protects network security because private networks are not advertised.

Correct Answers: B, F

By not revealing the internal IP addresses, NAT adds some security to the inside network -> F is correct.
NAT has to modify the source IP addresses in the packets -> E is not correct.
Connection from the outside of the network through a “NAT” network is more difficult than a more network because IP addresses of inside hosts are hidden -> C is not correct.
In order for IPsec to work with NAT we need to allow additional protocols, including Internet Key Exchange (IKE), Encapsulating Security Payload (ESP) and Authentication Header (AH) -> more complex -> A is not correct.
By allocating specific public IP addresses to inside hosts, NAT eliminates the need to re-address the inside hosts -> B is correct.
NAT does conserve addresses but not through host MAC-level multiplexing. It conserves addresses by allowing many private IP addresses to use the same public IP address to go to the Internet -> C is not correct.