IPv4 Connectivity Checker
Check the IPv4 address observed by our server from your current connection, inspect its four 8-bit octets in decimal, binary, and hexadecimal, and verify whether an address is public, private (RFC 1918), or shared Carrier-Grade NAT (RFC 6598).
Observed IPv4 Address (32-bit Dotted-Decimal)
216.73.216.25
Four-Octet Structure Breakdown (4 × 8-bit Unsigned Bytes = 32 Bits)
Octet 1 (Bits 0–7)
216
Bin: 11011000
Hex: 0xD8
Octet 2 (Bits 8–15)
73
Bin: 01001001
Hex: 0x49
Octet 3 (Bits 16–23)
216
Bin: 11011000
Hex: 0xD8
Octet 4 (Bits 24–31)
25
Bin: 00011001
Hex: 0x19
Address Scope Classification
Public / Global Unicast IPv4
RFC 791 / IANA Global Unicast · Routable: Yes
32-Bit Unsigned Integer & Hex
3628718105
Hex: 0xD849D819
Reverse DNS Zone Pointer
25.216.73.216.in-addr.arpa
How IPv4 Addressing Works on Modern Dual-Stack and CGNAT Networks
IPv4 (defined in IETF RFC 791) uses 32-bit addresses written as four decimal octets separated by periods (for example, 49.44.0.1). Because a 32-bit integer space holds at most 4,294,967,296 addresses—and hundreds of millions are reserved for private LANs and multicast—Indian and global ISPs have exhausted unallocated public IPv4 pools.
To keep IPv4 websites and applications working for hundreds of millions of mobile and broadband users, providers deploy Carrier-Grade NAT (CGNAT) or NAT64/DNS64 translation. Outbound IPv4 connections succeed normally, but your router WAN interface often receives an internal 100.64.0.0/10 address rather than a dedicated public IPv4 address.
What This IPv4 Check Verifies
- Server-observed IPv4: Displays the source IPv4 address observed at our edge load balancer when your browser requests this page.
- Octet & scope verification: Decomposes any IPv4 address into its 32-bit binary structure and checks the IANA Special-Purpose Registry. Compare with IPv6 Connectivity Checker and IPv4 vs IPv6.
Technical Specifications & Protocol Facts
Authoritative parameters, dimensions, and IETF RFC compliance
| Parameter / Dimension | Technical Specification | Standard / Authority |
|---|---|---|
| Address Bit Length | 32 bits (4 bytes) written as 4 decimal octets (0–255) | RFC 791 |
| Total Address Space | 2³² = 4,294,967,296 total IPv4 addresses | IANA IPv4 Registry |
| CGNAT Shared Range | 100.64.0.0/10 (100.64.0.0 – 100.127.255.255) | RFC 6598 |
| Private LAN Ranges | 10.0.0.0/8, 172.16.0.0/12, and 192.168.0.0/16 | RFC 1918 |
Frequently Asked Questions
Concise answers verified against IANA, APNIC, and IETF protocol standards
How is a 32-bit IPv4 address structured into octets?
An IPv4 address consists of 32 binary bits split into four 8-bit bytes called octets. Each octet is written as a decimal number from 0 to 255 separated by dots.
Why does my router WAN status show a 100.x.x.x IP while this checker shows another IPv4?
If your router WAN IP lies between 100.64.0.0 and 100.127.255.255, your ISP uses Carrier-Grade NAT (RFC 6598). Your router has a shared carrier address, and external websites see the ISP gateway public IPv4.
Can I inspect any custom IPv4 address on this page?
Yes. In addition to inspecting your live connection, you can enter any IPv4 address into the local octet inspector to view its 32-bit integer value, binary octets, and RFC scope.
Related Network Tools & Technical Guides
Contextual utilities and reference documentation verified for this workflow
Diagnostic & Calculation Utilities
- IPv6 Checker
Inspect 128-bit IPv6 reachability, eight-hextet structure, compressed/expanded form, and Indian dual-stack context.
- IP Address Validator & Classifier
Verify syntactic validity and inspect whether an IP is globally routable or reserved in an IANA special-purpose block.
- IP Address Converter
Convert IPv4 and IPv6 addresses across canonical, expanded, decimal integer, hexadecimal, binary, and reverse ARPA forms.
- Subnet Calculator
Calculate network address, broadcast, usable host range, wildcard mask, and 32-bit binary mask for /0 to /32.
IPv4 Checker · Canonical: https://ipaddresslookup.in/ipv4-check · Reviewed: 2026-11-01
Reviewer: IPAddressLookup.in Technical Network Utility Group · Stateless Privacy · Accuracy & Data Limits