CCNA 4 R&S: Connecting Networks Chapter 5 v5.0 Exam Answers 2014

1 Typically, which network device would be used to perform NAT for a corporate environment?

DHCP server
host device
router
server
switch

2 What is the group of public IPv4 addresses used on a NAT-enabled router known as?

outside local addresses
inside local addresses
inside global addresses
outside global addresses

3 When NAT is employed in a small office, which address type is typically used for hosts on the local LAN?

private IP addresses
global public IP addresses
Internet-routable addresses
both private and public IP addresses

4 Which version of NAT allows many hosts inside a private network to simultaneously use a single inside global address for connecting to the Internet?

PAT
static NAT
dynamic NAT
port forwarding

5 Which type of NAT maps a single inside local address to a single inside global address?

dynamic
static
port address translation
overloading

6 Several key servers in an organization must be directly accessible from the Internet. What addressing policy should be implemented for these servers?

Use dynamic NAT to provide addresses for the servers.
Place all of the servers in their own Class C private subnet.
Use DHCP to assign addresses from the pool of Class B addresses.
Assign static internal addresses and public external addresses to each of the servers

7 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.

8

Refer to the exhibit. What has to be done in order to complete the static NAT configuration on R1?

R1 should be configured with the command ip nat inside source static 209.165.200.1 192.168.11.11.
R1 should be configured with the command ip nat inside source static 209.165.200.200 192.168.11.11.
Interface S0/0/0 should be configured with the command ip nat outside.
Interface Fa0/0 should be configured with the command no ip nat inside.

9

Refer to the exhibit. R1 is configured for NAT as displayed. What is wrong with the configuration?

Access-list 1 is misconfigured.
NAT-POOL2 is not bound to ACL 1.
Interface Fa0/0 should be identified as an outside NAT interface.
The NAT pool is incorrect.

10 Which statement accurately describes dynamic NAT?

It always maps a private IP address to a public IP address.
It provides an automated mapping of inside local to inside global IP addresses.
It provides a mapping of internal host names to IP addresses.
It dynamically provides IP addressing to internal hosts.

11 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

12 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.

13 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.

14

Refer to the exhibit. What will be the effect of entering the command that is shown in the exhibit on R2 as part of the dynamic NAT configuration?

It will define a pool of addresses for translation.
It will identify an inside NAT interface.
It will bind NAT-POOL1 with ACL 1.
It will define the source ACL for the external interface.

15 Which configuration would be appropriate for a small business that has the public IP address of 209.165.200.225/30 assigned to the external interface on the router that connects to the Internet?

access-list 1 permit 10.0.0.0 0.255.255.255
ip nat inside source list 1 interface serial 0/0/0 overload

access-list 1 permit 10.0.0.0 0.255.255.255
ip nat pool comp 192.0.2.1 192.0.2.8 netmask 255.255.255.240
ip nat inside source list 1 pool comp

access-list 1 permit 10.0.0.0 0.255.255.255
ip nat pool comp 192.0.2.1 192.0.2.8 netmask 255.255.255.240
ip nat inside source list 1 pool comp overload

access-list 1 permit 10.0.0.0 0.255.255.255
ip nat pool comp 192.0.2.1 192.0.2.8 netmask 255.255.255.240
ip nat inside source list 1 pool comp overload
ip nat inside source static 10.0.0.5 209.165.200.225

16 What are two required steps to configure PAT? (Choose two.)

Define a pool of global addresses to be used for overload translation.
Define a standard access list denying the addresses that should be translated.
Define the range of ports to be used.
Identify the inside interface.
Define a standard access list that allow the outside global addresses to be used.

17

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

18 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.

19 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.

20

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

21

Refer to the exhibit. The NAT configuration applied to the router is as follows:
ERtr(config)# access-list 1 permit 10.0.0.0 0.255.255.255
ERtr(config)# ip nat pool corp 209.165.201.6 209.165.201.30 netmask 255.255.255.224
ERtr(config)# ip nat inside source list 1 pool corp overload
ERtr(config)# ip nat inside source static 10.10.10.55 209.165.201.4
ERtr(config)# interface gigabitethernet 0/0
ERtr(config-if)# ip nat inside
ERtr(config-if)# interface serial 0/0/0
ERtr(config-if)# ip nat outside

Based on the configuration and the output shown, what can be determined about the NAT status within the organization?

Dynamic NAT is working, but static NAT is not.
Static NAT is working, but dynamic NAT is not.
NAT is working.
Not enough information is given to determine if both static and dynamic NAT are working. *

22 Based on the configuration and the output shown, what can be determined about the NAT status within the organization?

NAT is working.
Static NAT is working, but dynamic NAT is not.
Dynamic NAT is working, but static NAT is not.
Not enough information is given to determine if both static and dynamic NAT are working.

23

Open the PT Activity. Perform the tasks in the activity instructions and then answer the question.
What problem is causing PC-A to be unable to communicate with the Internet?

The static route should not reference the interface, but the outside address instead.
This router should be configured to use static NAT instead of PAT.
The ip nat inside source command refers to the wrong interface.
The access list used in the NAT process is referencing the wrong subnet.
The NAT interfaces are not correctly assigned.

24

Place the options in the following order:
– not scored –
step 5
step 2
step 4
step 1
step 3

25 
What are two of the required steps to configure PAT? (Choose two.)

Create a standard access list to define applications that should be translated.
Identify the inside interface.*
Define the range of source ports to be used.
Define the hello and interval timers to match the adjacent neighbor router.
Define a pool of global addresses to be used for overload translation.*