What is Subnetting | FLSM | VLSM in Definitions FacebookTwitter We use subnetting for reduce wastage of IP. There to Two Types of Subnetting. 1) FLSM = Fix Length Subnet Mask 2) VLSM =Variable subnet mask Tip : For Learn Sub-netting start from Class C. Its very easy , if you do practice daily. Categories: Definitions Tags: Class C FLSM Mask 2 Nbsp Subnet Mask subnetting