2-11: NAT

Question 1

What is a disadvantage of NAT?

Answer 1

There is no end-to-end addressing.

Question 1

If a host with an internal IP of 192.168.10.10 attempts to send a packet to an external server at the IP 209.165.200.254 across a router running dynamic NAT, what is the second step in resolving the address?

Answer 1

Router checks the NAT configuration to determines if this packet should be translated.

Question 1

The Inside Local address is usually what?

Answer 1

An RFC 1918 address

Question 2

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

Answer 2

Interface S0/0/0 should be configured with the command ip nat outside.

Question 2

Private IPs are often referred to as

Answer 2

Non-routeable or RFC1918 addresses

Question 4

If a host with an internal IP of 192.168.10.10 attempts to send a packet to an external server at the IP 209.165.200.254 across a router running dynamic NAT, what is the third step in resolving the address?

Answer 4

If there is no translation entry for this IP address, the router determines that the internal address must be translated.

Question 5

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

Answer 5

Assign static internal addresses and public external addresses to each of the servers.

Question 6

If a host with an internal IP of 192.168.10.10 attempts to send a packet to an external server at the IP 209.165.200.254 across a router running dynamic NAT, what is the fourth step in resolving the address?

Answer 6

The router selects an available global address from the dynamic address pool.

Question 6

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

R2(config)# ip nat inside source list 1 pool NAT-POOL1

Answer 6

It will bind NAT-POOL1 with ACL 1.

Question 8

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

Answer 8

static

Question 9

What is the purpose of port forwarding?

Answer 9

Port forwarding allows an external user to reach a service on a private IPv4 address that is located inside a LAN.

Question 9

Which statement accurately describes dynamic NAT?

Answer 9

It provides an automated mapping of inside local to inside global IP addresses.

Question 9

What is the purpose of the command marked with an arrow shown in the partial configuration output of a Cisco broadband router?

Answer 9

Defines which addresses can be translated

Question 10

The Outside Global address is what?

Answer 10

The Reachable IP of a host on the internet.

Question 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?

Answer 12

The company has more private IP addresses than available public IP addresses.

Question 13

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?

Answer 13

A NAT pool named corp that defines the starting and ending public IP addresses

Question 15

If a host with an internal IP of 192.168.10.10 attempts to send a packet to an external server at the IP 209.165.200.254 across a router running dynamic NAT, what is the first step in resolving the address?

Answer 15

The host sends packets that request a connection to the address.

Question 16

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?

Answer 16

The request to the server for the seventh user fails.

Question 17

What is a characteristic of unique local addresses?

Answer 17

They allow sites to be combined without creating any address conflicts.

Question 18

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

Answer 18

Not enough information is given to determine if both static and dynamic NAT are working.

Question 19

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

Answer 19

Router

Question 20

The Inside Global address is what?

Answer 20

The Public IP inside host is given as it exits NAT

Question 22

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

Answer 22

Inside global addresses

Question 23

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

Answer 23

Private IP addresses

Question 25

What are two required steps to configure PAT?

Answer 25

Define a pool of global addresses to be used for overload translation. Identify the inside interface.

Question 26

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?

Answer 26

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

Question 27

If a host with an internal IP of 192.168.10.10 attempts to send a packet to an external server at the IP 209.165.200.254 across a router running dynamic NAT, what is the fifth step in resolving the address?

Answer 27

The router replaces the internal address with the translated global address.

Question 28

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

Answer 28

NAT-POOL2 is not bound to ACL 1.

Question 29

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

Answer 29

PAT

Question 30

Based on the output that is shown, what type of NAT has been implemented?

Answer 30

PAT using an external interface