**Contents**show

## How many subnets and hosts per subnet can you get from the network 172.16 0.0 18?

0.0/18 – why **4 subnets**.

## What is the broadcast address 172.16 0.0 16?

IP Subnet Calculator

CIDR block | IP range (network – broadcast) | Subnet Mask |
---|---|---|

172.16.0.0/17 | 172.16.0.0 – 172.16.127.255 | 255.255.128.0 |

172.16.0.0/16 | 172.16.0.0 – 172.16.255.255 | 255.255.0.0 |

172.16.0.0/15 | 172.16.0.0 – 172.17.255.255 | 255.254.0.0 |

172.16.0.0/14 | 172.16.0.0 – 172.19.255.255 | 255.252.0.0 |

## How do you calculate 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 maximum number of hosts in a 19 subnet?

Class A

Network Bits | Subnet Mask | Number of Hosts |
---|---|---|

/18 | 255.255.192.0 | 16382 |

/19 | 255.255.224.0 | 8190 |

/20 | 255.255.240.0 | 4094 |

/21 | 255.255.248.0 | 2046 |

## How many host addresses are available in the 128 network?

Subnet Mask Cheat Sheet

Addresses | Hosts | |
---|---|---|

/ 25 | 128 |
126 |

/ 24 | 256 | 254 |

/ 23 | 512 | 510 |

/ 22 | 1024 | 1022 |

## How many hosts per network can exist in each of the IP address classes AB and C?

Each network supports a **maximum of 16,777,214 (2 ^{24} -2) hosts per network**. You must subtract two because the base network represents host “0”, and the last host on the network is actually used for 1s (“broadcast”) and may not be assigned to any host.

## What is the maximum number of IP address that can be assigned to hosts on a local subnet that uses the 255.255 255.224 subnet mask?

The subnet mask defines the number of hosts available on a subnet. The mask 255.255. 255.224 leaves five bits for the host address, which could theoretically hold **32 addresses**.

## What is the maximum number of IP addresses that can be assigned to hosts on a local subnet with 255.255 255.224 subnet mask?

A /27 (255.255. 255.224) is 3 bits on and 5 bits off. This provides 8 subnets, each with **30** hosts.

## How many subnets and hosts per subnet can you get from the network?

255.255. 240.0 is a /20 subnet mask, therefore there are 4 borrowed bits (from the 3rd octet). Number of hosts on each subnetwork = (2 to the power 4) – 2 (i.e. 4 bits in host portion of address), which gives **14**.