In IPv4 classful addressing, which of the following IP address ranges corresponds to Class B?
Class B IP addresses have first bits '10', placing the first octet in range 128 to 191. Hence 128.0.0.0 to 191.255.255.255.
An organization is granted a block of IPv4 addresses with prefix 192.168.1.0/24. If the organization needs to create 8 equal subnets, what is the new subnet mask?
To create 8 subnets ($2^3$ = 8), we borrow 3 bits from the host part. New prefix = 24 + 3 = 27 (/27). Subnet mask = 255.255.255.224.
What is the network ID for an IP address 172.16.45.10 with subnet mask 255.255.240.0 (/20)?
Subnet mask 255.255.240.0 in third octet is 240 = 11110000. IP third octet is 45 = 00101101. Bitwise AND: 45 & 240 = 32 (00100000). Thus Network ID = 172.16.32.0.
In CIDR notation 200.10.20.0/22, how many total assignable IP host addresses are available in this network?
Prefix length is 22 bits, leaving 32 - 22 = 10 bits for host portion. Total addresses = $2^10$ = 1024. Usable host addresses = 1024 - 2 (Network ID and Directed Broadcast) = 1022.
Which of the following IP addresses is a private IPv4 address as per RFC 1918?
RFC 1918 Private Ranges: 10.0.0.0/8 (10.0.0.0 - 10.255.255.255), 172.16.0.0/12 (172.16.0.0 - 172.31.255.255), and 192.168.0.0/16 (192.168.0.0 - 192.168.255.255). 172.20.10.5 falls in 172.16-172.31 range.