Here i am going to post some mostly asked question in CCNA exam the Bold text is the answer. maybe my answer are wrong but i tried my best to give you correct answer. if any one think that the answer which i gave its not correct then please feedback me.

1. What are three advantages of NAT implementations? (Choose three.)

  1. improved security
  2. improved router performance
  3. decreased processor load
  4. improved scalability
  5. universal application compatibility
  6. sharing few public IP addresses with many hosts

2. In an 8 bit binary number, what is the total number of combinations of the eight bits?

  1. 128
  2. 254
  3. 255
  4. 256
  5. 512
  6. 1024

3. Which option shows the proper notation for an IPv6 address?

  1. 2001,0db8,3c55,0015,abcd,ff13
  2. 2001-0db8-3c55-0015-abcd-ff13
  3. 2001.0db8.3c55.0015.abcd.ff13
  4. 2001:0db8:3c55:0015::abcd:ff13

4. What are two reasons that NAT was developed? (Choose two.)

  1. to preserve registered public IP addresses
  2. to allow users on the public Internet to access local networks
  3. to provide a method for privately addressed LANs to participate in the Internet
  4. to make routing protocols operate more efficiently
  5. to allow private addresses to be routed on the public Internet
  6. to reduce overhead and CPU usage on gateway routers

5. Which IPv4 class of addresses provides the most networks?

  1. Class A
  2. Class B
  3. Class C
  4. Class D
  5. Class E

6. Which statement describes NAT overload or PAT?

  1. Each internal address is dynamically translated to an individual external IP address.
  2. A single internal address is always translated to the same unique external IP address.
  3. Many internal addresses can be translated to a single IP address using different port assignments.
  4. Many internal addresses are statically assigned a single IP address and port to use for communications.

7. Which two statements describe classful IP addresses? (Choose two.)

  1. It is possible to determine which class an address belongs to by reading the first bit.
  2. The number of bits used to identify the hosts is fixed by the class of the network.
  3. Only Class A addresses can be represented by high-order bits 100.
  4. Up to 24 bits can make up the host portion of a Class C address.
  5. Up to 24 bits can be used to identify unique networks.
  6. Three of the five classes of addresses are reserved for multicasts and experimental use.

8. Which statement accurately describes public IP addresses?

  1. Public addresses cannot be used within a private network.
  2. Public IP addresses must be unique across the entire Internet.
  3. Public addresses can be duplicated only within a local network.
  4. Public IP addresses are only required to be unique within the local network.
  5. Network administrators are free to select any public addresses to use for network devices that access the Internet.

9. Which port numbers are used by PAT to create unique global addresses?

  1. 255 and below
  2. 1024 and below
  3. 1025 and above
  4. 64,000 and above

10. Static NAT works by mapping a specific inside local IP address to what other specific address type?

  1. inside global
  2. outside local
  3. outside global
  4. private IP address

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