myip VS dns.toys

Why not use protocols which are purposely designed to report mapped IP address like STUN? It's faster as UDP exchange is shorter than 3-way TCP handshake (or even TCP+TLS handshake).

Here is an implementation which uses parallel STUN queries to report address reliably as fast as possible: https://github.com/Snawoot/myip

For Windows; Try the myip binary

Try this client with public STUN servers; https://github.com/Snawoot/myip/releases/tag/v1.2.0 it has precompiled binaries for multiple platforms.

Addresses on the "far side" of a NAT aren't inherently visible to the host. The only way to find out is to reach out to an external service, and have that service report back what source IP address they see your request coming from. Usually people use a web API, but there might be other ways.

This kind of service is exactly what STUN servers are made for to be used alongside webrtc. There are a plethora of unauthenticated STUN servers around, and while there's still room for abuse, the protocol is a bit more lightweight than full-blown http requests, and faster, too!

I've dabbled with doing this on my own, but I've found `myip` to do the job nicely and without hassle:

https://github.com/Snawoot/myip

I had some auto-tests for VPN app which were relying on similar web-service to check own IP address. One day service become unavailable and autotests got broken. IIRC it was (https://canihazip.com/s)

I decided to solve this task in a fast and reliable fashion, so I made a tool which discovers own IP address using major public STUN servers: https://github.com/Snawoot/myip

Program issues parallel queries to public STUN servers to determine public IP address and returns result as soon as quorum of matching responses reached.

Works fast and reliable, especially compared to services requiring HTTPS:

  user@dt1:~> time curl https://api.ipify.org

In addition to the others, there is also https://www.dns.toys/

It's always amusing to see DNS "hackery"[1] like this, and always makes me go back to DNS Toys (https://www.dns.toys/), which generated a huge discussion on HN a year ago [2]

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[1] well, it's not really hackery if you're being pedantic, since it's doing what the spec allows it to do

[2] DNS Toys (946 points): https://news.ycombinator.com/item?id=31704789

#1: Which of the below DNS Servers track user data & logs #2: Is there any reason to care about DNSSEC in 2022 as regards choice of registrar and DNS host? #3: Useful utilities and toys over DNS | 6 comments

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