GitHub - ygvn/IPv6-Subnet-Calculator-Tool-JavaFX: IPv6 Subnet Calculator / Tool application lets you plan/subnet your assigned IPv6 address for all 128 bits.
Site24x7 Subnet Calculator for IPv4 and IPv6: Network IP Calculations Made Simple - Site24x7 Blog
4. IPv6 Subnetting - IPv6 Address Planning [Book]
How IPv4 mask bit settings define a match (Example)