Network Address and Port Translation (NAPT)

Question 1

What is NAT?

Answer 1

1. Mechanism to translate (map) one address space by another
2. Allow many private IP addresses to be represented by some smaller number of public IP addresses
3. Similar to CIDR (Classless Inter-Domain Routing)

Question 2

Advantages of NAT?

Answer 2

1. Conserves legally registered addresses
2. Remedies address overlap events
3. Increases flexibility when connecting to the internet
4. Eliminates address renumbering as a network evolves

Question 3

Disadvantages of NAT?

Answer 3

1. Translation results in switching path delays
2. Causes loss of end-to-end Ip traceability
3. Certain applications will not function with NAT enabled

Question 4

Types of NAT?

Answer 4

1. Static
2. Dynamic
3. Overloading(Port Address Translation PAT/NAPT)

Question 5

What is Inside Local for NAT?

Answer 5

Source host inside address before translation(RFC 1918 Address)

Question 6

What is Outside Local for NAT?

Answer 6

Address from which source host is known on the internet (router interface)

Question 7

What is Inside Global for NAT?

Answer 7

Source host address used after translation to get onto the internet

Question 8

What is Outside Global for NAT?

Answer 8

Address of outside destination host and, again the real internet address.