Borrow 5 bits (for 30 subnets total).
we need to borrow 7 bits to subnet 172.16.100.0 to have at least 500 hosts and the subnet mask will be 255.255.254.0
4 bits
Dally.
62 hosts.
Given a Class C network: 200.1.1.0 We want 5 subnets, each with 30 hosts on it. How many bits to borrow ? How many bits to leave? What is the subnet mask? ( in dot notation and in CIDR notation)
You would need at least 9 bits to borrow. Since 8 bits gives only 255 the additional bit will get you 256. Adding 256 + 128 gives you at least 384 subnets or hosts.
The maximum number of host bits that can be borrowed from a class A address is 22 (technically you could borrow 23 but the resulting network would be useless). A class A address uses 8 bits for its network address and 24 bits for its host addresses. Class A uses a subnet mask of 255.0.0.0 You can only borrow 22 bits (instead of 24) because a valid network requires 4 addresses: A network address, two host addresses and a broadcast address. These networks would result in 30 bits used for the network address and 2 bits used for the host addresses. These networks use a subnet mask of 255.255.255.252
Same as subnetting any other class, or a classless network. From the bits originally reserved for the host (16 bits, in the case of a class B address), you "borrow" some bits, that is, you use them to specify the subnet. The remaining bits specify an individual host within a subnet.
When you borrow bits for a subnet you are intruding into the client portion of an IP address. As a result, you will lose clients in your network because the "borrowed" portion becomes the extended network prefix. This allows you to separate your bigger network into smaller, logical networks (subnets). The number of bits borrowed will indicate the total number of smaller subnets that you can support in your network. In each case, regardless of class of address, borrowing 4 bits gives a total of 14 subnets (in the classical sense) and 16 subnets (in Cisco).
19,200 bits.
16 bits