CCNA 2 Chapter 9 Exam Answers
1 What is the primary purpose of NAT?
conserve IPv4 addresses*
increase network security
allow peer-to-peer file sharing
enhance network performance
2 Which method is used by a PAT-enabled router to send incoming packets to the correct inside hosts?
It uses the destination TCP or UDP port number on the incoming packet*
It uses the source TCP or UDP port number on the incoming packet
It uses the source IP address on the incoming packet
It uses a combination of the source TCP or UDP port number and the destination IP address on the incoming packet
3 What are two benefits of NAT? (Choose two.)
It saves public IP addresses
It adds a degree of privacy and security to a network*
It increases routing performance
It makes troubleshooting routing issues easier
It makes tunneling with IPsec less complicated
4 What is a disadvantage of NAT?
There is no end-to-end addressing.*
The router does not need to alter the checksum of the IPv4 packets.
The internal hosts have to use a single public IPv4 address for external communication.
The costs of readdressing hosts can be significant for a publicly addressed network.
5 What is an advantage of deploying IPv4 NAT technology for internal hosts in an organization?
makes internal network access easy for outside hosts using UDP
provides flexibility in designing the IPv4 addressing scheme*
increases the performance of packet transmission to the Internet
enables the easy deployment of applications that require end-to-end traceability
6 Refer to the exhibit. Which address or addresses represent the inside global address?
10.1.1.2
192.168.0.100
209.165.20.25*
any address in the 10.1.1.0 network
7 Refer to the exhibit. A technician is configuring R2 for static NAT to allow the client to access the web server. What is a possible reason that the client PC cannot access the web server?
Interface S0/0/0 should be identified as the outside NAT interface*
Interface Fa0/1 should be identified as the outside NAT interface
The IP NAT statement is incorrect
The configuration is missing a valid access control list
8 A network administrator configures the border router with the command R1(config)# ip nat inside source list 4 pool corp. What is required to be configured in order for this particular command to be functional?
a NAT pool named corp that defines the starting and ending public IP addresses*
an access list named corp that defines the private addresses that are affected by NAT
an access list numbered 4 that defines the starting and ending public IP addresses
ip nat outside to be enabled on the interface that connects to the LAN affected by the NAT
a VLAN named corp to be enabled and active and routed by R1
9 When dynamic NAT without overloading is being used, what happens if seven users attempt to access a public server on the Internet when only six addresses are available in the NAT pool?
No users can access the server
The request to the server for the seventh user fails*
All users can access the server
The first user gets disconnected when the seventh user makes the request
10 What is defined by the ip nat pool command when configuring dynamic NAT?
the pool of global address*
the range of internal IP addresses that are translated
the pool of available NAT servers
the range of external IP addresses that internal hosts are permitted to access
11 Refer to the exhibit. What is the purpose of the command marked with an arrow shown in the partial configuration output of a Cisco broadband router?
defines which addresses can be translated*
defines which addresses are allowed into the router
defines which addresses are assigned to a NAT pool
defines which addresses are allowed out of the router
12 A network engineer has configured a router with the command ip nat inside source list 4 pool corp overload. Why did the engineer use the overload option?
The company has more private IP addresses than available public IP addresses*
The company needs to have more public IP addresses available to be used on the Internet
The company router must throttle or buffer traffic because the processing power of the router is not enough to handle the normal load of external-bound Internet traffic
The company has a small number of servers that should be accessible by clients from the Internet
13 What are two of the required steps to configure PAT? (Choose two.)
Define a pool of global addresses to be used for overload translation*
Create a standard access list to define applications that should be translated
Define the range of source ports to be used
Identify the inside interface*
Define the hello and interval timers to match the adjacent neighbor router
14 What is the major benefit of using NAT with Port Address Translation?
It allows external hosts access to internal servers
It improves network performance for real-time protocols
It allows many internal hosts to share the same public IPv4 address*
It provides a pool of public addresses that can be assigned to internal hosts
15 What is the purpose of port forwarding?
Port forwarding allows an external user to reach a service on a private IPv4 address that is located inside a LAN*
Port forwarding allows users to reach servers on the Internet that are not using standard port numbers
Port forwarding allows an internal user to reach a service on a public IPv4 address that is located outside a LAN
Port forwarding allows for translating inside local IP addresses to outside local addresses
16 A network administrator is configuring a static NAT on the border router for a web server located in the DMZ network. The web server is configured to listen on TCP port 8080. The web server is paired with the internal IP address of 192.168.5.25 and the external IP address of 209.165.200.230. For easy access by hosts on the Internet, external users do not need to specify the port when visiting the web server. Which command will configure the static NAT?
R1(config)# ip nat inside source static tcp 192.168.5.25 80 209.165.200.230 8080
R1(config)# ip nat inside source static tcp 192.168.5.25 8080 209.165.200.230 80*
R1(config)# ip nat inside source static tcp 209.165.200.230 80 192.168.5.25 8080
R1(config)# ip nat inside source static tcp 209.165.200.230 8080 192.168.5.25 80
17 What is a characteristic of unique local addresses?
They allow sites to be combined without creating any address conflicts*
They are designed to improve the security of IPv6 networks
Their implementation depends on ISPs providing the service
They are defined in RFC 3927
18 Which statement describes IPv6 ULAs?
They conserve IPv6 address space
They are assigned by an ISP
They begin with the fe80::/10 prefix
They are not routable across the Internet*
19 Refer to the exhibit. Based on the output that is shown, what type of NAT has been implemented?
dynamic NAT with a pool of two public IP addresses
PAT using an external interface*
static NAT with one entry
static NAT with a NAT pool
20 Match the steps with the actions that are involved when an internal host with IP address 192.168.10.10 attempts to send a packet to an external server at the IP address 209.165.200.254 across a router R1 that is running dynamic NAT. (Not all options are used.)
21 Fill in the blank. Do not use abbreviations.
NAT overload is also known as ———
Correct Answer: Port Address Translation*