Forcing IPv4/IPv6

[xfbs]

Is it possible for force IPv4 or IPv6 connections?

[anton-dutov]

up

[ta3pks]

wow it has been some time since this issue opened with no reply

[ycd]

I'd also love to have an example of this.

Technically using AF_INET6 should be enough, but i couldn't find a struct in the library that i can build my own HttpConnector to create a client or something close to that.

You must be incredibly busy @seanmonstar and you don't have to answer this but it would be awesome to have a minimal example or a little guiding.

[seanmonstar]

It's not immediately obvious, but if you specify the local_address option, the connection will use the same IP version as the locally bound address.

[ycd]

Thanks for the response, i'm leaving an example for future visitors.

use std::net::IpAddr;
use std::{collections::HashMap, str::FromStr};

#[tokio::main]
async fn main() -> Result<(), Box<dyn std::error::Error>> {
    let client = reqwest::Client::builder()
        .local_address(IpAddr::from_str("2001:0db8:85a3:0000:0000:8a2e:0370:7334")?) 
        .build()?;

    let resp = client
        .get("https://httpbin.org/ip")
        .send()
        .await?
        .json::<HashMap<String, String>>()
        .await?;

    println!("{:#?}", resp);
    Ok(())
}

[ycd]

I think we can close this @seanmonstar :+1:

[univerz]

I think we can close this

please no, i would like to run my code on any machine :) (& force ipv4).

[ta3pks]

@univerz how to force ipv4 is explained above just add .local_addr("0.0.0.0:0".parse().unwrap()) and you are good to go

[redactedontop]

and if you need to force ipv6, just do .local_address("[::]:0".parse().ok()).

[flisky]

Maybe we can use a custom dns_resolver to only resolve IPv4 or IPv6 addresses?

[redactedontop]

Just use the methods me and ta3pks said.

[Architector4]

I may be mistaken, but this does not appear to be working with a SOCKS5 proxy. Even when trying to force an IPv4 connection with the method above, it appears to still try the IPv6 address over the proxy.

I have a proxy server I wish to use that does not do DNS by itself and cannot connect through IPv6, but my machine I'm using reqwest from does and can. I don't want to muck with my machine's DNS settings to globally exclude IPv6 connectivity just for this one use case of mine, but other than that, I have no idea how to get this to work.

Edit: it appears just removing IPv6 DNS servers doesn't work. My machine uses systemd-resolved and I think it just uses IPv4 DNS servers over TLS and gets IPv6 addresses from them anyway. Killing any IPv6 connectivity from my machine entirely seems to make it work, but that's really painfully unacceptable lol