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: 9.129.248.0/21
Addresses: 2048 (2¹¹)
First IP: 9.129.248.0 (0.248.129.9.in-addr.arpa)
Last IP: 9.129.255.255 (255.255.129.9.in-addr.arpa)

/8 Operated By: ARIN

Related Networks

9.0.0.0/8
8.0.0.0/8
10.0.0.0/8
9.129.240.0/20
9.129.248.0/32
9.129.255.255/32

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