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: 128.128.6.40/31
Addresses: 2 (2¹)
First IP: 128.128.6.40 (40.6.128.128.in-addr.arpa)
Last IP: 128.128.6.41 (41.6.128.128.in-addr.arpa)

/8 Operated By: ARIN

Related Networks

128.0.0.0/8
127.0.0.0/8
129.0.0.0/8
128.128.6.40/30
128.128.6.40/32
128.128.6.41/32

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