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: 8.3.129.0/31
Addresses: 2 (2¹)
First IP: 8.3.129.0 (0.129.3.8.in-addr.arpa)
Last IP: 8.3.129.1 (1.129.3.8.in-addr.arpa)

/8 Operated By: ARIN

Related Networks

8.0.0.0/8
7.0.0.0/8
9.0.0.0/8
8.3.129.0/30
8.3.129.0/32
8.3.129.1/32

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