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: 128.128.1.40/30
Addresses: 4 (2²)
First IP: 128.128.1.40 (40.1.128.128.in-addr.arpa)
Last IP: 128.128.1.43 (43.1.128.128.in-addr.arpa)

/8 Operated By: ARIN

Related Networks

128.0.0.0/8
127.0.0.0/8
129.0.0.0/8
128.128.1.40/29
128.128.1.40/32
128.128.1.43/32

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