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.
network class network address number of subnets required number of host per subnet
255.255.255.0
that gives you 16 subnets with 14 usable IPs for hosts that is because one is for subnet and one for broadcas in that subnet for example: 192.168.1.0/28 - subnet number 192.168.1.15 -broadcast number usable IPs for hosts - IPs between them that is 14
254
1
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)
A class A would give you the most flexibility in terms of subnets and hosts per subnet. You could use up to 23 bits of information for subnets.
255.255.252.0
255.255.252.0
Borrow 5 bits (for 30 subnets total).
From the 16 bits reserved for the host, you "lend" 3 bits for the subnet. That gives you the possibility of dividing into eight subnets. The remaining 13 bits indicate the host in each subnet. - To see the complete steps in more detail, do some Internet searching on subnetting.
A Class C IP address has 24 bits for network and 8 bits for host. So to have a subnet mask of 26 bits, you will need to use 2 bits from host part.Number of subnets is given by the formula : 2^(no. of bits used from host part).Hence number of subnets in this case would be = 2^2 = 4.For e.g. if the class C IP address is 200.168.210.0the 4 subnet addresses would be :11001000.10101000.11010010.00000000 = 200.168.210.011001000.10101000.11010010.01000000 = 200.168.210.6411001000.10101000.11010010.10000000 = 200.168.210.12811001000.10101000.11010010.11000000 = 200.168.210.192Note: The digits in bold are the mask bits.