IPv4 Subnet Calculator

This calculator and tool allows you to type an IP address in and get information on a particular subnet. Enter an IP or range in CIDR notation.

Network: 217.128.12.0/25
Addresses: 128 (2⁷)
First IP: 217.128.12.0 (0.12.128.217.in-addr.arpa)
Last IP: 217.128.12.127 (127.12.128.217.in-addr.arpa)

/8 Operated By: RIPE NCC

Related Networks

217.0.0.0/8
216.0.0.0/8
218.0.0.0/8
217.128.12.0/24
217.128.12.0/32
217.128.12.127/32

You can also use some of the other examples such as:

0.0.0.0/0
1.0.0.0/8
127.0.0.1
30.0.0.0/8
192.168.0.0/16