10.0.0.0/8), Class B (172.16.0.0/12), or Class C (192.168.0.0/16). Addresses in the 100.64.0.0/10 range represent ISP Carrier-Grade NAT (RFC 6598) and cannot be reached locally, while 169.254.0.0/16 (APIPA / RFC 3927) indicates that your computer failed to obtain a DHCP lease from your router. Use the analyzer below to verify any candidate IP address and launch its local administration panel.
IANA & RFC IPv4 Special-Purpose Address Allocations
| RFC Standard | Address Range | CIDR Block | Total Addresses | Routability Scope | Architectural Purpose |
|---|---|---|---|---|---|
| RFC 1918 Class A | 10.0.0.0 – 10.255.255.255 | 10.0.0.0/8 | 16,777,216 IPs | Private LAN Only | Large enterprise networks, Comcast/Rogers home gateways |
| RFC 1918 Class B | 172.16.0.0 – 172.31.255.255 | 172.16.0.0/12 | 1,048,576 IPs | Private LAN Only | Medium campus networks, Docker/container bridges |
| RFC 1918 Class C | 192.168.0.0 – 192.168.255.255 | 192.168.0.0/16 | 65,536 IPs | Private LAN Only | Global consumer home Wi-Fi routers (192.168.1.1, 192.168.0.1) |
| RFC 6598 Shared Space | 100.64.0.0 – 100.127.255.255 | 100.64.0.0/10 | 4,194,304 IPs | ISP Carrier Only (Non-Routable WAN) | Carrier-Grade NAT (CGNAT) multiplexing subscribers upstream |
| RFC 3927 Link-Local | 169.254.0.0 – 169.254.255.255 | 169.254.0.0/16 | 65,536 IPs | Single Segment Link-Local | Automatic Private IP Addressing (APIPA) on DHCP failure |
| RFC 1122 Loopback | 127.0.0.0 – 127.255.255.255 | 127.0.0.0/8 | 16,777,216 IPs | Host-Internal Only | Localhost inter-process communication (IPC) |
| RFC 5737 Documentation | 192.0.2.0/24, 198.51.100.0/24, 203.0.113.0/24 | /24 subnets | 768 IPs | Non-Routable Example Space | Technical documentation examples (TEST-NET-1, 2, 3) |
| RFC 3171 Multicast | 224.0.0.0 – 239.255.255.255 | 224.0.0.0/4 | 268,435,456 IPs | Multicast Group Scope | mDNS (224.0.0.251), SSDP UPnP (239.255.255.250), OSPF |
What This Address Checker Verifies
In standard TCP/IP networking, Layer 3 IPv4 addresses carry specific routing semantics enforced by operating system network stacks:
- Dotted-Decimal Syntax: Validates that the input contains exactly 4 octets separated by decimal points, with every numerical value residing strictly between 0 and 255.
- RFC 1918 Private Scopes: Differentiates Class A (
10.0.0.0/8), Class B (172.16.0.0/12), and Class C (192.168.0.0/16) from publicly routable internet space. - Carrier-Grade NAT (RFC 6598): Identifies
100.64.0.0/10addresses used upstream by Internet Service Providers. - APIPA DHCP Failure (RFC 3927): Flags
169.254.x.xaddresses indicating your client computer received no response from the router's internal DHCP server daemon.
Next Steps for Router Administration
Instant Router IP Finder — Probe your active local network to detect your exact gateway IP in <150ms.
Subnet & CIDR Calculator — Calculate network boundaries, usable host pools, and binary masks.
Router Login Not Working Troubleshooting — Resolve browser connection errors step-by-step.
Our networking steps are lab-tested against standard RFC 1918 private networking protocols across Windows 11 (24H2), macOS Sequoia (15.1), iOS 18, and Android 15. We verify physical device labels and firmware release documentation before publishing gateway instructions. Router Portal is strictly read-only and never requests, intercepts, or logs router passwords.