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: 81.255.128.0/31
Addresses: 2 (2¹)
First IP: 81.255.128.0 (0.128.255.81.in-addr.arpa)
Last IP: 81.255.128.1 (1.128.255.81.in-addr.arpa)

/8 Operated By: RIPE NCC

Related Networks

81.0.0.0/8
80.0.0.0/8
82.0.0.0/8
81.255.128.0/30
81.255.128.0/32
81.255.128.1/32

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