Why is a subnet mask needed?

Why is a subnet mask needed?

A subnet mask is used to divide an IP address into two parts. One part identifies the host (computer), the other part identifies the network to which it belongs. To better understand how IP addresses and subnet masks work, look at an IP address and see how it’s organized.

What is Interface subnet?

A subnetwork or subnet is a logical subdivision of an IP network. Addresses in the range 198.51. 100.0 to 198.51. 100.255 belong to this network. The IPv6 address specification 2001:db8::/32 is a large address block with 296 addresses, having a 32-bit routing prefix.

How do I assign a subnet mask?

Steps

1. To specify a subnet mask for an interface, enter the following command: ifconfig interface_name netmask mask.
2. To change the subnet mask for an interface that has been configured with a primary and an alias address, enter the following command for each IP address: ifconfig interface_name IP address netmask mask.

What is standard subnet mask?

Most home networks use the default subnet mask of 255.255. 255.0. However, an office network may be configured with a different subnet mask such as 255.255. 255.192, which limits the number of IP addresses to 64.

What are the functions of subnet mask?

The function of a subnet mask is to extract the network ID portion of an IP destination address and determine whether an IP address exists on the local network or whether it must be routed outside the local network. If the extracted network ID matches the local network ID, the destination is located on the local network.

How do you calculate subnet mask?

A more mathematical way to express the the subnet mask calculation is: current value = value on the left (previous value) + power of 2 of this column. It should take about 1 minute to do this when the exam starts. It will be extremely useful all through the exam to double check any IP and subnet.

How to determine a custom subnet mask?

Determining The Custom Subnet Mask Using Subnetting Tables. Now, what could be easier than that? Well, you could simply refer to the subnetting summary tables. Find the table for the appropriate class, and then find the row that you selected in the previous step that matches the number of subnet ID bits you want to use. You can see the matching subnet mask right there. (Hey, it’s good to know how to do it yourself! You may not always have tables to refer to!)

Is a subnet mask the same as netmask?

The “Netmask”, “subnet mask”, or simply “mask” are all the same thing: A mask that tells software which IPs belong to that network an which don’t.