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: 51.0.0.242/31
Addresses: 2 (2¹)
First IP: 51.0.0.242 (242.0.0.51.in-addr.arpa)
Last IP: 51.0.0.243 (243.0.0.51.in-addr.arpa)

/8 Operated By: RIPE NCC

Related Networks

51.0.0.0/8
50.0.0.0/8
52.0.0.0/8
51.0.0.240/30
51.0.0.242/32
51.0.0.243/32

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