How to Calculate Subnet Mask from IP Address Step by Step - Expert Network Consultant
Subnet Calculator
Gip – IP calculator for GNOME desktop environment | Debian Admin
GitHub - ygvn/IPv6-Subnet-Calculator-Tool-JavaFX: IPv6 Subnet Calculator / Tool application lets you plan/subnet your assigned IPv6 address for all 128 bits.
IPv4 Subnet Calculator Console Version - TerrorFlatRider