What is my IP address

• What is my IP address
  • Features
  • Endpoints
  • DNS discovery
  • Build
  • Usage
  • Examples
    • Run a default TCP server
    • Run a TLS (HTTP/2) and enable What is my DNS
    • Run an HTTP/3 server
    • Run a default TCP server with a custom template and trust a pair of custom headers set by an upstream proxy
  • Download
  • Docker
    • Run a container locally using test databases
    • From Docker Hub

[!NOTE]
Since version 2.3.0, the application includes an optional client DNS discovery

Just another "what is my IP address" service, including geolocation, TCP open port checking, and headers information. Written in go with high performance in mind, it uses gin which uses httprouter a lightweight high performance HTTP multiplexer.

Take a look at ifconfig.es a live site using whatismyip and the DNS discovery enabled.

Get your public IP easily from the command line:

curl ifconfig.es
127.0.0.1

curl -6 ifconfig.es
::1

Get the IP of your DNS provider:

curl -L dns.ifconfig.es
2a04:e4c0:47::67 (Spain / OPENDNS)

Features

• TLS and HTTP/2.
• Experimental HTTP/3 support. HTTP/3 requires a TLS server running (-tls-bind), as HTTP/3 starts as a TLS connection that then gets upgraded to UDP. The UDP port is the same as the one used for the TLS server.
• Beta DNS discovery: A best-effort approach to discovering the DNS server that is resolving the client's requests.
• Can run behind a proxy by trusting a custom header (usually X-Real-IP) to figure out the source IP address. It also supports a custom header to resolve the client port, if the proxy can only add a header for the IP (for example a fixed header from CDNs) the client port is shown as unknown.
• IPv4 and IPv6.
• Geolocation info including ASN. This feature is possible thanks to maxmind GeoLite2 databases. In order to use these databases, a license key is needed. Please visit Maxmind site for further instructions and get a free license.
• Checking TCP open ports.
• High performance.
• Self-contained server that can reload GeoLite2 databases and/or SSL certificates without stop/start. The hup signal is honored.
• HTML templates for the landing page.
• Text plain and JSON output.

Endpoints

• https://ifconfig.es/
• https://ifconfig.es/client-port
• https://ifconfig.es/json (this is the same as curl -H "Accept: application/json" https://ifconfig.es/)
• https://ifconfig.es/geo
  • https://ifconfig.es/geo/city
  • https://ifconfig.es/geo/country
  • https://ifconfig.es/geo/country_code
  • https://ifconfig.es/geo/latitude
  • https://ifconfig.es/geo/longitude
  • https://ifconfig.es/geo/postal_code
  • https://ifconfig.es/geo/time_zone
• https://ifconfig.es/asn
  • https://ifconfig.es/asn/number
  • https://ifconfig.es/asn/organization
• https://ifconfig.es/all
• https://ifconfig.es/headers
  • https://ifconfig.es/<header_name>
• https://ifconfig.es/scan/tcp/<port_number>
• https://dns.ifconfig.es

DNS discovery

The DNS discovery works by forcing the client to make a request to <uuid>.dns.ifconfig.es this DNS request is handled by a microdns server included in the whatismyip binary. In order to run the discovery server, a configuration file in the following form has to be created:

---
domain: dns.example.com
redirect_port: ":8000"
resource_records:
  - "1800 IN SOA xns.example.com. hostmaster.example.com. 1 10000 2400 604800 1800"
  - "3600 IN NS xns.example.com."
ipv4:
  - "127.0.0.2"
ipv6:
  - "aaa:aaa:aaa:aaaa::1"

The DNS authority for example.com has delegated the subdomain zone dns.example.com to the server running the whatismyip service.

The client can request the URL dns.example.com by following the redirection curl -L dns.example.com.

To avoid the redirection, you can provide a valid URL, for example, for the real ifconfig.es:

curl $(uuidgen).dns.ifconfig.es

curl $(cat /proc/sys/kernel/random/uuid).dns.ifconfig.es

Build

Golang >= 1.22 is required.

make build

Usage

Usage of whatismyip:
  -bind string
        Listening address (see https://pkg.go.dev/net?#Listen) (default ":8080")
  -enable-http3
        Enable HTTP/3 protocol. HTTP/3 requires --tls-bind set, as HTTP/3 starts as a TLS connection that then gets upgraded to UDP. The UDP port is the same as the one used for the TLS server.
  -enable-secure-headers
        Add sane security-related headers to every response
  -geoip2-asn string
        Path to GeoIP2 ASN database
  -geoip2-city string
        Path to GeoIP2 city database
  -resolver string
        Path to the resolver configuration. It actually enables the resolver for DNS client discover.
  -template string
        Path to template file
  -tls-bind string
        Listening address for TLS (see https://pkg.go.dev/net?#Listen)
  -tls-crt string
        When using TLS, path to certificate file
  -tls-key string
        When using TLS, path to private key file
  -trusted-header string
        Trusted request header for remote IP (e.g. X-Real-IP). When using this feature if -trusted-port-header is not set the client port is shown as 'unknown'
  -trusted-port-header string
        Trusted request header for remote client port (e.g. X-Real-Port). When this parameter is set -trusted-header becomes mandatory
  -version
        Output version information and exit

Examples

Run a default TCP server

./whatismyip -geoip2-city ./test/GeoIP2-City-Test.mmdb -geoip2-asn ./test/GeoLite2-ASN-Test.mmdb

Run a TLS (HTTP/2) and enable What is my DNS

./whatismyip -geoip2-city ./test/GeoIP2-City-Test.mmdb -geoip2-asn ./test/GeoLite2-ASN-Test.mmdb \
             -bind "" -tls-bind :8081 -tls-crt ./test/server.pem -tls-key ./test/server.key \
             -resolver ./test/resolver.yml

Run an HTTP/3 server

./whatismyip -geoip2-city ./test/GeoIP2-City-Test.mmdb -geoip2-asn ./test/GeoLite2-ASN-Test.mmdb \
             -bind "" -tls-bind :8081 -tls-crt ./test/server.pem -tls-key ./test/server.key -enable-http3

Run a default TCP server with a custom template and trust a pair of custom headers set by an upstream proxy

./whatismyip -geoip2-city ./test/GeoIP2-City-Test.mmdb -geoip2-asn ./test/GeoLite2-ASN-Test.mmdb \
             -trusted-header X-Real-IP -trusted-port-header X-Real-Port -template mytemplate.tmpl

Download

Download the latest version from github

Docker

An ultra-light (~4MB) image is available on docker hub. Since version 2.1.2, the binary is compressed using upx.

Run a container locally using test databases

make docker-run

From Docker Hub

docker run --tty --interactive --rm \
    -v $PWD/<path to city database>:/tmp/GeoIP2-City-Test.mmdb:ro \
    -v $PWD/<path to ASN database>:/tmp/GeoLite2-ASN-Test.mmdb:ro -p 8080:8080 \
    dcarrillo/whatismyip:latest \
      -geoip2-city /tmp/GeoIP2-City-Test.mmdb \
      -geoip2-asn /tmp/GeoLite2-ASN-Test.mmdb