You might be a System Administrator, Developer, Infra Designer, Architect or a Capacity Manager by role, but getting quick information on your VLAN or available subnet is always a headache; and we make mistakes in hurry. Since this subnet information is so important and bit nasty sometimes, we all use different method to get this information like subnet size, subnet mask, available hosts, default router IP to be used, broadcast IP etc.
For quick reference I used to keep a table as it will be easy for me to guess the basic details of the subnet. But for complex details, we use some spreadsheet with formulas and filters. So I thought to keep a list of useful portals which will help you to calculate most of the subnet details in a quick and easy way.
cidr.xyz
One of my favorite tool to explain when some Project managers or Project leads argue with VLAN information. Always we should have details to show why we cannot use/we must use this subnet. This website will show you a colorful data for subnets and details.
IP Calculator by jodies.de/ipcalc
Another simple and easy tool for subnet calculation but with more details on binary information.
IP Subnet Calculator by Calculator.net
More detailed result with class A,B and C network and subnets for the given mask value.
Subnet-calculator.com
Simple Interface with quick calculator; you won’t get list of IP’s or subnets but will show the details in application window.
Interested to read more ? You might also intrested to read The Ultimate Guide to Subnetting.