How many 20 subnets can be formed?

Subnet Cheat Sheet – 24 Subnet Mask, 30, 26, 27, 29, and other IP Address CIDR Network References

CIDR	Subnet mask	# of usable IP addresses
/21	255.255.248.0	2,046
/20	255.255.240.0	4,094
/19	255.255.224.0	8,190
/18	255.255.192.0	16,382

Which subnet mask can be shown with 20?

255.255.240.0
Class A

Network Bits	Subnet Mask	Number of Subnets
/18	255.255.192.0	1024 (1022)
/19	255.255.224.0	2048 (2046)
/20	255.255.240.0	4096 (4094)
/21	255.255.248.0	8192 (8190)

What are the minimum host bits needed if the network has 20 hosts?

So back to answer our initial question of the minimum subnet size to accommodate 20 hosts, the minimum number of host bits required is 5 bits (2^5 = 32).

How do you calculate the number of subnets?

To calculate the number of possible subnets, use the formula 2n, where n equals the number of host bits borrowed. For example, if three host bits are borrowed, then n=3. 23 = 8, so eight subnets are possible if three host bits are borrowed.

What is the subnet mask for 25?

Subnet Mask Cheat Sheet

	Addresses	Netmask
/26	64	255.255.255.192
/25	128	255.255.255.128
/24	256	255.255.255.0
/23	512	255.255.254.0

What is a 24 bit subnet mask?

A class C network would have a subnet mask of 255.255. 255.0 which means that 24 bits are used for the network. In CIDR notation this is designated by a /24 following the IP address.

How do you calculate subnet bits?

Calculate the subnet bits by looking at the final 8-bit binary word of the 32-bit binary subnet mask. If the final 8-bit binary word is 10000000, then there is one subnet bit and therefore 25 mask bits. If it is 11000000, then there are two subnet bits and therefore 26 mask bits.

What are the minimum host bits needed if the network has 25 hosts?

Minimum subnet size to accommodate a number of hosts

No. of Host Bits	Equivalent prefix length	Number of usable IP addresses
5	/27	25-2 = 30
6	/26	26-2 = 62
7	/25	27-2 = 126
8	/24	28-2 = 254

How many bits do I need for a 30 subnet?

Subnet Mask Cheat Sheet

	Addresses	Netmask
/ 30	4	255.255.255.252
/ 29	8	255.255.255.248
/ 28	16	255.255.255.240
/ 27	32	255.255.255.224

How do I create a subnet mask?

To calculate the subnet mask, convert an IP address to binary, perform the calculation and then convert back to the IPv4 decimal number representation known as a dotted quad. The same subnetting procedure works for IPv6 addresses.

How to calculate the number of subnets?

How to Calculate Subnets. Subnets and Hosts Borrow 2 bits. S S H H H H H H # of subnets = 2 2 = 4 Subnet mask = 2 bits = 128 + 64 = 192 Range of hosts = 2 6 = 64 TT Range Useable Range Network ID 0 – 63 64 – 127 65 – 126 128 – 191 129 – 190 Broadcast 192 – 255 Address.

What is a subnet mask and how does it work?

With a subnet mask, devices can look at an IP address, and figure out which parts are the network bits and which are the host bits. Then using those things, it can figure out the best way for those devices to communicate. If you’ve poked around the network settings on your router or computer, you’ve likely seen this number: 255.255.255.0.

What is the default subnet mask for a Class C IP address?

Class C IP Addresses For Class C IP addresses, the first three octets (24 bits / 3 bytes) represent the network ID and the last octet (8 bits / 1 bytes) is the host ID. Class C IP Addresses range from 192.0.0.0 to 223.255.255.255, with a default subnet mask of 255.255.255.0 (or /24 in CIDR).

How many hosts do I need for a 20 bit network?

You need 5 bits, or 32-5 = 27, i.e. a /27 network! With a class C to get hosts, I count from 128 backwards cutting it in half each step. So 128, 64, 32. It has to be 32 hosts because half of 32 is 16, not enough for 20. That’s 3 bits borrowed.