IP Address Analyzer

Verbose subnet calculator with address classification flags.

Monitor this automatically

NetTests can run this check on a schedule, preserve historical results, compare changes over time, and alert you the moment something breaks.

Start monitoring free → See all monitoring products

Frequently Asked Questions

How is IP Address Analyzer different from Subnet Calculator?

Subnet Calculator focuses on CIDR subnet math — network address, broadcast, host range, and mask. IP Address Analyzer is more verbose: it additionally classifies the address (unicast, multicast, loopback, private, link-local, reserved, APIPA) and shows IPv4-mapped IPv6 representations, making it better for understanding what a specific address is rather than subnetting.

What is an APIPA address?

APIPA (Automatic Private IP Addressing) addresses are in the 169.254.0.0/16 range. A device assigns itself an APIPA address when it can't reach a DHCP server — it means the device has no valid network configuration and cannot communicate beyond the local link. Seeing 169.254.x.x on an interface indicates a DHCP failure.

What does 'private' vs 'public' address classification mean?

RFC 1918 defines three private IP ranges not routed on the public internet: 10.0.0.0/8, 172.16.0.0/12, 192.168.0.0/16. These are used inside LANs and NAT environments. Everything else is public (routable). Sending a packet to a private address from the internet will be dropped at the originating router or ISP boundary.