Bogon IP Detector
Check if any IP address is a bogon (martian) address - an IP that should never appear on the public internet. Enter an IPv4 or IPv6 address to instantly see if it falls into private (RFC 1918), loopback, link-local, multicast, CGNAT, documentation, reserved, or other special-purpose ranges. All detection happens locally in your browser with complete privacy - no signup required.
Enter any IP address to instantly check if it is a bogon (martian) address - an IP that should never appear on the public internet. Detects all major bogon ranges per RFC standards. All processing happens locally in your browser.
Enter an IP address above to check if it is a bogon
Click any example button to test with a sample IP address
Why Use Our Bogon IP Detector?
Instant Bogon Detection
Enter any IPv4 or IPv6 address and instantly determine if it is a bogon (martian) address. Our tool checks against all major bogon IP ranges defined in RFC standards, including private (RFC 1918), loopback, link-local, multicast, broadcast, CGNAT, documentation, benchmarking, and reserved ranges.
Comprehensive Range Coverage
Covers all known bogon ranges for both IPv4 and IPv6. IPv4 bogon checks include 14 distinct ranges from RFC 1122, 1918, 5737, 6598, 2544, 5771, and more. IPv6 bogon checks include 10 ranges from RFC 4291, 4193, 3849, 3056, 4380, and others. New ranges are added as standards evolve.
Severity-Based Classification
Each bogon range is classified with a severity level - High (critical security risks like private IPs on the public internet), Medium (important but less critical like CGNAT), Low (special-purpose addresses), and Informational (addresses with specific context like 6to4). Helps you prioritise security actions.
100% Private & Client-Side
All IP address checks are performed entirely in your browser using JavaScript. The IP addresses you enter never leave your device - no uploads, no server processing, no logging. Your network data stays completely private and secure at all times.
Common Use Cases for Bogon IP Detector
Network Security Auditing
Audit firewall and router configurations by checking if bogon IP addresses are being blocked at the perimeter. Verify that private RFC 1918 addresses, loopback ranges, and other martian addresses are not reaching your public-facing network interfaces.
Bogon Filter List Maintenance
When maintaining bogon filter lists for network infrastructure (BGP prefix filters, ACL rules, iptables, nftables), use this tool to verify individual IP addresses against current bogon ranges to ensure your filters are working correctly.
IP Address Validation in Applications
Validate IP addresses in your applications to ensure they are legitimate public addresses before processing. Check user-submitted IPs, IP-based access control lists, or IP addresses from external data sources to filter out bogon addresses.
Network Diagnostics & Troubleshooting
When troubleshooting network connectivity issues, check if unexpected IP addresses in your logs are bogon addresses. This helps identify misconfigured devices, routing loops, or potential spoofing attempts in your network.
Security Incident Investigation
During security incident investigations, check source IPs from logs against bogon ranges to identify potentially spoofed or forged IP addresses. Bogon source addresses in attack logs often indicate IP spoofing or reflection attacks.
ISP & Datacenter Operations
Network operators can use the bogon detector to verify that customer traffic is not coming from or going to bogon addresses. Essential for maintaining BCP 38 (Network Ingress Filtering) compliance and preventing IP spoofing on network infrastructure.
Understanding Bogon IP Addresses
What is a Bogon IP Address?
A bogon IP address (also called a martian address) is an IP address that should never appear on the public internet. These addresses are reserved by the Internet Assigned Numbers Authority (IANA) for special purposes such as private networks, loopback interfaces, multicast, documentation, benchmarking, or future use. The term "bogon" comes from "bogon filtering" - the practice of filtering out packets with obviously invalid source or destination addresses at network borders.
When a packet with a bogon source address appears on the public internet, it often indicates IP address spoofing, a misconfigured router, or a network security incident. Internet service providers, datacenters, and enterprise networks implement bogon filtering as part of BCP 38 (Network Ingress Filtering) best practices to prevent spoofing and improve network security.
How Our Bogon IP Detector Works
Our bogon detector checks IP addresses against comprehensive lists of known bogon address ranges defined by multiple RFC standards.
- IPv4 parsing - The IP address is converted to a 32-bit integer and checked against 14 distinct bogon CIDR ranges including private networks (10.0.0.0/8, 172.16.0.0/12, 192.168.0.0/16), loopback (127.0.0.0/8), CGNAT (100.64.0.0/10), link-local (169.254.0.0/16), multicast (224.0.0.0/4), documentation ranges, benchmarking range, and reserved space.
- IPv6 parsing - The IPv6 address is expanded from its compressed form and checked against 10 special-purpose ranges including the unspecified address (::/128), loopback (::1/128), unique local (fc00::/7), link-local (fe80::/10), multicast (ff00::/8), documentation (2001:db8::/32), and others such as 6to4 and Teredo tunneling.
- Severity classification - Each detected bogon range is labelled with a severity: high (critical - should never be seen), medium (important - limited use cases), low (special-purpose - context-dependent), or info (informational - unusual but not necessarily malicious).
Common Bogon Ranges and Their Usage
Our bogon detector checks these major categories of addresses:
- Private Networks (RFC 1918) - The three private IPv4 ranges (10.0.0.0/8, 172.16.0.0/12, 192.168.0.0/16) and IPv6 Unique Local Addresses (fc00::/7) are the most commonly seen bogon ranges. These are valid within private networks but must be filtered at internet borders.
- Loopback & Link-Local - Loopback addresses (127.0.0.0/8, ::1) are used for local host communication. Link-local addresses (169.254.0.0/16, fe80::/10) are auto-assigned and never routed. Both are high-severity bogon ranges.
- Documentation & Benchmarking - TEST-NET ranges (192.0.2.0/24, 198.51.100.0/24, 203.0.113.0/24) and the documentation IPv6 prefix (2001:db8::/32) are reserved for documentation and examples. The benchmarking range (198.18.0.0/15) is used by network testing tools.
- Multicast & Reserved - Multicast ranges (224.0.0.0/4, ff00::/8) are for one-to-many delivery, not unicast routing. The reserved range (240.0.0.0/4, formerly Class E) is set aside for future use by IANA.
Privacy & Security
All bogon detection is performed entirely in your browser using JavaScript. The IP addresses you enter are never sent to any server, never stored in any database, and never leave your device. This ensures complete privacy when checking internal network addresses, private IPs, or any other addresses you choose to inspect.
The tool works completely offline after the initial page load. No data is logged, no analytics track your queries, and no server processes your input. Your network information stays yours alone.
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Frequently Asked Questions About Bogon IP Detector
A bogon IP address (also called a martian address) is an IP address that should never appear on the public internet. These addresses are reserved by IANA for special purposes such as private networks, loopback interfaces, multicast, documentation, or future use. The term "bogon" is often used in network security contexts to describe packets that have obviously invalid source or destination addresses.
Filtering bogon addresses is a critical network security best practice (BCP 38). Bogon filtering prevents IP address spoofing, reduces the risk of DDoS reflection attacks, stops traffic from misconfigured networks, and helps maintain clean routing tables. Most ISPs and large networks implement bogon filtering at their border routers to block obviously invalid traffic before it enters their network.
Private IP addresses (RFC 1918) are a subset of bogon addresses. All private IPs are bogons, but not all bogons are private IPs. Bogon addresses include private ranges (10.0.0.0/8, 172.16.0.0/12, 192.168.0.0/16), loopback (127.0.0.0/8), link-local (169.254.0.0/16), multicast (224.0.0.0/4), broadcast (255.255.255.255/32), documentation ranges, reserved space, and IPv6 special-purpose addresses.
Absolutely. All IP address checking is performed entirely in your browser using client-side JavaScript. The IP addresses you enter are never sent to any server, never stored in any database, and never leave your device. The tool works completely offline after the initial page load, ensuring complete privacy for any addresses you check.
Yes. Our bogon IP detector fully supports both IPv4 and IPv6 addresses. For IPv6, it detects 10 special-purpose ranges including the unspecified address, loopback, IPv4-mapped addresses, NAT64 translation, documentation prefix, 6to4, Teredo, unique local addresses, link-local unicast, and multicast. Simply enter any valid IPv6 address to check if it is a bogon.
High severity indicates critical bogon ranges that should never be seen on the public internet, such as private networks, loopback, and broadcast addresses. Medium severity covers important ranges like CGNAT and documentation. Low severity includes special-purpose addresses like multicast and benchmarking. Informational covers addresses that are unusual or deprecated but may have legitimate special-purpose use cases.
The most critical bogon ranges to filter are the private RFC 1918 ranges (10.0.0.0/8, 172.16.0.0/12, 192.168.0.0/16), loopback (127.0.0.0/8), link-local (169.254.0.0/16), CGNAT (100.64.0.0/10), and multicast (224.0.0.0/4). These cover the vast majority of bogon traffic seen on the public internet. Many routers and firewalls include default bogon filter rules for these ranges.
Yes, our Bogon IP Detector is 100% free to use with no signup required, no usage limits, and no hidden charges. Check as many IP addresses as you need - there are no restrictions on the number of queries. No registration, no API keys, and no premium features. All processing happens locally in your browser.