Network Address Translation (NAT) Flashcards by vadim craevschi

Which command would you place on the interface connected to the Internet?
A) ip nat inside
B) ip nat outside
C) ip outside global
D) ip inside local

Answer: B) ip nat outside

How well did you know this?

Not at all

Perfectly

Which command will show you all the translations active on your router?
A) show ip nat translations
B) show ip nat statistics
C) debug ip nat
D) clear ip nat translations *

Answer: A) show ip nat translations

How well did you know this?

Not at all

Perfectly

Which command would you place on the interface on a private network?
A) ip nat inside
B) ip nat outside
C) ip outside global
D) ip inside local

Answer: A) ip nat inside

How well did you know this?

Not at all

Perfectly

Port Address Translation is also termed what?
A) NAT Fast
B) NAT Static
C) NAT Overload
D) Overloading Static

Answer: C) NAT Overload

How well did you know this?

Not at all

Perfectly

When creating a pool of global addresses, which of the following can be used instead of the netmask command?
A) / (slash notation)
B) prefix-length
C) no mask
D) block-size

Answer: B) prefix-length

How well did you know this?

Not at all

Perfectly

Which of the following would be a good starting point for troubleshooting if your router is not translating?
A) Reboot.
B) Call Cisco.
C) Check your interfaces for the correct configuration.
D) Run the debug all command.

Answer: C) Check your interfaces for the correct configuration.

How well did you know this?

Not at all

Perfectly

Which command will show you the summary of the NAT configuration?
A) show ip nat translations
B) show ip nat statistics
C) debug ip nat
D) clear ip nat translations *

Answer: B) show ip nat statistics

How well did you know this?

Not at all

Perfectly

Which of the following is considered to be the destination host before translation?
A) Inside local
B) Outside local
C) Inside global
D) Outside global

Answer: A) Inside local

How well did you know this?

Not at all

Perfectly

Which of the following is considered to be the address after translation?
A) Inside local
B) Outside local
C) Inside global
D) Outside global

Answer: D) Outside global

How well did you know this?

Not at all

Perfectly

Which are considered the methods of NAT?
Static
IP NAT pool
Dynamic
NAT double-translation
Overload

A) 1 and 6
B) 3 only
C) 1, 3, and 5
D) All of the above

Answer: C) 1, 3, and 5

How well did you know this?

Not at all

Perfectly

Which type of NAT address is used to represent an inside host to the outside world?
A) Inside local
B) Inside global
C) Outside local
D) Outside global

Answer: B) Inside global

How well did you know this?

Not at all

Perfectly

What is the purpose of NAT?
A) To provide security by hiding internal IP addresses
B) To conserve public IP addresses
C) To allow multiple devices to share a single public IP address
D) All of the above

Answer: D) All of the above

How well did you know this?

Not at all

Perfectly

Which command is used to configure NAT overload?
A) ip nat inside source list 1 interface FastEthernet0/0 overload
B) ip nat inside source static 192.168.1.10 10.0.0.1
C) ip nat pool mypool 10.0.0.1 10.0.0.10 netmask 255.255.255.0
D) ip nat inside source list 1 pool mypool

Answer: A) ip nat inside source list 1 interface FastEthernet0/0 overload

How well did you know this?

Not at all

Perfectly

Which of the following is a valid private IP address?
A) 192.168.1.1
B) 172.16.5.5
C) 10.0.0.1
D) All of the above

Answer: D) All of the above

How well did you know this?

Not at all

Perfectly

What does the overload keyword enable in NAT configuration?
A) Static NAT
B) Dynamic NAT
C) Port Address Translation (PAT)
D) One-to-one mapping

Answer: C) Port Address Translation (PAT)

How well did you know this?

Not at all

Perfectly

Which command is used to clear all NAT translations?
A) clear ip nat translations *
B) clear ip nat statistics
C) clear ip nat translations
D) clear ip nat

Answer: A) clear ip nat translations *

How well did you know this?

Not at all

Perfectly

What is the default behavior of NAT if no access list is specified?
A) NAT is disabled
B) All traffic is translated
C) Only traffic from specified IP addresses is translated
D) NAT is applied to all outgoing traffic

Answer: B) All traffic is translated

How well did you know this?

Not at all

Perfectly

Which of the following is a disadvantage of NAT?
A) Increased security
B) Simplified network design
C) Difficulty in end-to-end traceability
D) Conservation of IP addresses

Answer: C) Difficulty in end-to-end traceability

How well did you know this?

Not at all

Perfectly

Which command is used to define an access list for NAT?
A) access-list 1 permit 192.168.1.0 0.0.0.255
B) ip access-list standard 1
C) ip nat inside source list 1 interface FastEthernet0/0 overload
D) ip nat pool mypool 10.0.0.1 10.0.0.10 netmask 255.255.255.0

Answer: A) access-list 1 permit 192.168.1.0 0.0.0.255

How well did you know this?

Not at all

Perfectly

What is the role of the ip nat inside command?
A) Defines the inside interface for NAT
B) Defines the outside interface for NAT
C) Enables NAT on the router
D) Specifies the NAT pool

Answer: A) Defines the inside interface for NAT

How well did you know this?

Not at all

Perfectly

What is the role of the ip nat outside command?
A) Defines the inside interface for NAT
B) Defines the outside interface for NAT
C) Enables NAT on the router
D) Specifies the NAT pool

Answer: B) Defines the outside interface for NAT

Which of the following is a valid NAT configuration?
A) ip nat inside source list 1 interface FastEthernet0/0 overload
B) ip nat inside source static 192.168.1.10 10.0.0.1
C) ip nat inside source list 1 pool NATPOOL
D) All of the above

✅ Answer: D) All of the above
(Each command represents a valid NAT configuration: dynamic PAT, static NAT, and dynamic NAT using a pool.)

What type of NAT maps one private IP to one public IP permanently?
A) Dynamic NAT
B) Static NAT
C) NAT Overload
D) PAT

✅ Answer: B) Static NAT

Which NAT term describes the IP address assigned to a host on the internal network?
A) Inside global
B) Outside global
C) Inside local
D) Outside local

✅ Answer: C) Inside local

Which NAT term refers to the IP address used on the Internet to represent an internal host? A) Inside local B) Inside global C) Outside global D) Public local

✅ Answer: B) Inside global

What is required for configuring dynamic NAT? A) An access list and an overload command B) An access list and a NAT pool C) A static mapping D) A routing protocol

✅ Answer: B) An access list and a NAT pool

Which command creates a NAT pool? A) ip nat pool name start-ip end-ip netmask subnet-mask B) nat pool create C) ip access-list pool D) ip nat inside overload

✅ Answer: A) ip nat pool name start-ip end-ip netmask subnet-mask

What does NAT do when there are no more available addresses in the pool for dynamic NAT? A) Drops packets B) Switches to overload C) Creates a temporary mapping D) Falls back to static NAT

✅ Answer: A) Drops packets

What protocol information does PAT use to map multiple IPs to a single address? A) IP only B) MAC address C) Port numbers D) Subnet mask

✅ Answer: C) Port numbers

How many inside local addresses can PAT map to a single inside global address? A) 1 B) 64 C) 1024 D) Many, using port numbers

✅ Answer: D) Many, using port numbers

Which type of NAT is best suited when you need to allow external users to access an internal server? A) Static NAT B) Dynamic NAT C) PAT D) Port Forwarding

✅ Answer: A) Static NAT (It provides a permanent 1:1 mapping between public and private IPs.)

What is a limitation of static NAT? A) It only supports TCP B) It requires a large number of public IPs C) It only supports one device D) It blocks return traffic

✅ Answer: B) It requires a large number of public IPs

In PAT, what happens when all port numbers are used? A) NAT stops translating new sessions B) NAT switches to dynamic NAT C) NAT starts using the next IP from the pool D) Router drops NAT configuration

✅ Answer: C) NAT starts using the next IP from the pool

What is one benefit of NAT? A) Slows routing B) Adds more IPv4 addresses C) Conserves public IPv4 addresses D) Reduces LAN performance

✅ Answer: C) Conserves public IPv4 addresses

Which NAT type translates many-to-many mappings? A) Static NAT B) Dynamic NAT C) PAT D) NAPT

✅ Answer: B) Dynamic NAT

How do you verify NAT translations on a Cisco router? A) show nat active B) show ip translations C) show ip nat translations D) debug ip

✅ Answer: C) show ip nat translations

What does NAT Overload require that Dynamic NAT does not? A) NAT pool B) Static IPs C) Port numbers D) ACL

✅ Answer: C) Port numbers

What is the purpose of an access list in NAT configuration? A) To secure the NAT process B) To match traffic for NAT C) To log NAT events D) To filter ICMP

✅ Answer: B) To match traffic for NAT

Which of the following is NOT a private IP range? A) 10.0.0.0 – 10.255.255.255 B) 172.16.0.0 – 172.31.255.255 C) 192.168.0.0 – 192.168.255.255 D) 169.254.0.0 – 169.254.255.255

✅ Answer: D) 169.254.0.0 – 169.254.255.255 (This is APIPA, not a private IP range.)

Which RFC defines private IPv4 address space? A) RFC 1234 B) RFC 1918 C) RFC 3927 D) RFC 951

✅ Answer: B) RFC 1918

Which NAT type allows multiple private IPs to share a single public IP using different ports? A) Static NAT B) Dynamic NAT C) PAT D) None

✅ Answer: C) PAT

What does NAT stand for? A) Network Allocation Table B) Network Address Translation C) New Address Technology D) None of the above

✅ Answer: B) Network Address Translation

What is the effect of this command? ip nat inside source static 192.168.1.10 203.0.113.10 A) Translates a public IP to many private IPs B) Enables overload C) Maps one private IP to one public IP D) Enables dynamic NAT

✅ Answer: C) Maps one private IP to one public IP

Which show command displays the number of active NAT sessions? A) show ip nat translations B) show ip nat statistics C) debug ip nat D) show ip interface brief

✅ Answer: B) show ip nat statistics

Which component is optional when configuring static NAT? A) Inside interface B) Outside interface C) Access-list D) IP mapping

✅ Answer: C) Access-list

NAT is usually configured on what type of device? A) Switch B) PC C) Router or Firewall D) Server

✅ Answer: C) Router or Firewall

What happens to return traffic in NAT? A) It's dropped B) It's statically routed C) NAT table uses the reverse mapping D) It must be manually forwarded

✅ Answer: C) NAT table uses the reverse mapping

Which address is typically not changed in NAT? A) Inside local B) Inside global C) Outside global D) Outside local

✅ Answer: C) Outside global (The external address is often left unchanged.)

PAT is most commonly used in which environment? A) Between two private networks B) On ISPs C) Small to medium businesses accessing the Internet D) Between VLANs

✅ Answer: C) Small to medium businesses accessing the Internet

In which NAT type is a new mapping created each time a session starts? A) Static NAT B) PAT C) Dynamic NAT D) Reverse NAT

✅ Answer: C) Dynamic NAT