Prefer IPv6.

[fernvenue]

Feature Proposed
Hi, thanks for the great tool! Sometimes I will use IPv6 only servers or services, and I have tried to use a IPv6 only address like ipv6.icanhazip.com, but unfortunately, rathole will still request A type first. So, could you please add a feature like prefer_ipv6 or ipv6_only for each connection or all connections?

Use Case
As I said above, we can use this feature for IPv6 only servers or services :)

[rapiz1]

Do you mean ipv6.icanhazip.com does not have an A-type record and you want to avoid the unnecessary DNS request? I see the usefulness of preferring ipv6 over ipv4 when A and AAAA both exist but don't think an additional A-type query will cause problems.

BTW, DNS lookup is currently handled by tokio::net::lookup_host

[fernvenue]

Sorry for the late reply. The problem here is that rathole will always request for an A type first. Now, if I want rathole to prefer IPv6, I have to disable resolving A type requests for a specific domain. Although this solves my problem to some extent, when I do this, rathole will continue to send meaningless type A requests and lose the ability to fall back to IPv4 in an environment where both IPv4 and IPv6 exist.

[rapiz1]

Got it. That's a useful feature

…

---Original--- From: ***@***.***> Date: Thu, Dec 8, 2022 16:01 PM To: ***@***.***>; Cc: "Yujia ***@***.******@***.***>; Subject: Re: [rapiz1/rathole] Prefer IPv6. (Issue #184) Sorry for the late reply. The problem here is that rathole will always request for an A type first. Now, if I want rathole to prefer IPv6, I have to disable resolving A type requests for a specific domain. Although this solves my problem to some extent, when I do this, rathole will continue to send meaningless type A requests and lose the ability to fall back to IPv4 in an environment where both IPv4 and IPv6 exist. — Reply to this email directly, view it on GitHub, or unsubscribe. You are receiving this because you commented.Message ID: ***@***.***>

[Stennsen]

I recently stumbled upon this project and tried to set it up on my machines.
I also got a Problem, with ipv4 being preferred by rathole and thus rathole tries to communicate with my ISPs NAT.
Is that feature already in development by someone? If not, I would be interested in contributing.

[fernvenue]

Hi @Stennsen, thanks for your reply! Currently there is no one working on this feature, I think that will be so great if you can contribute, and if you need someone to help you test anything, I'm glad to help :)