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: 4.128.240.0/21
Addresses: 2048 (2¹¹)
First IP: 4.128.240.0 (0.240.128.4.in-addr.arpa)
Last IP: 4.128.247.255 (255.247.128.4.in-addr.arpa)

/8 Operated By: ARIN

Related Networks

4.0.0.0/8
3.0.0.0/8
5.0.0.0/8
4.128.240.0/20
4.128.240.0/32
4.128.247.255/32

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