http://www.routemeister.net/projects/sipcalc/web.html


Display:
Everything
CIDR bitmap
Classful address information
CIDR address information
Classful bitmap
Extra networks
Split network (v4)
Verbose split (v4)
Verbose split (v6)
Basic IPv6 output
IPv4 compatible IPv6 information
IPv6 reverse DNS output
Split network (v6)