200-301 Question 89
Select 3A network administrator is configuring a private network for an organization. The administrator wants to assign IP addresses to devices that will not be directly reachable over the public internet. Which of the following IP address ranges would be appropriate for this private network?
- A
192.168.0.0 to 192.168.255.255
- B
172.16.0.0 to 172.31.255.255
- C
10.0.0.0 to 10.255.255.255
- D
203.0.113.0 to 203.0.113.255
- E
100.64.0.0 to 100.127.255.255
Show answer and explanation
Correct answers: A, B, C
Explanation
Private IPv4 address ranges are defined in RFC 1918 and are intended for use within private networks that will not be directly accessible from the public internet. The ranges 192.168.0.0/16, 172.16.0.0/12, and 10.0.0.0/8 are the designated private IPv4 address ranges. Other ranges, such as the TEST-NET-3 range (203.0.113.0/24) and CGNAT range (100.64.0.0/10), have specific purposes and are not suitable for general private network use.
- A. Correct.
192.168.0.0 to 192.168.255.255 is a private IPv4 address range as defined by RFC 1918, suitable for private networks.
- B. Correct.
172.16.0.0 to 172.31.255.255 is a private IPv4 address range as defined by RFC 1918, suitable for private networks.
- C. Correct.
10.0.0.0 to 10.255.255.255 is a private IPv4 address range as defined by RFC 1918, suitable for private networks.
- D. Incorrect.
203.0.113.0 to 203.0.113.255 is part of the TEST-NET-3 range as defined by RFC 5737 and is reserved for documentation purposes, not private use.
- E. Incorrect.
100.64.0.0 to 100.127.255.255 is part of the Carrier-Grade NAT (CGNAT) range, as defined by RFC 6598, and is not considered private addressing for general internal use.