Skip to main content
DHT address lookup publishes and resolves endpoint records on the BitTorrent Mainline distributed hash table. The records are the same signed records that DNS address lookup uses. The difference is where they are stored. DNS address lookup publishes them to a hosted server and resolves over DNS, while DHT address lookup puts them on the BitTorrent Mainline DHT. That removes the dependency on a hosted server: any endpoint can publish and resolve without a central party, at the cost of slower lookups than DNS. DHT address lookup is not enabled by default. It lives in the separate iroh-mainline-address-lookup crate, which you add alongside iroh. 
[dependencies]
iroh = "1"
iroh-mainline-address-lookup = "0.4"
Add the DhtAddressLookup to the endpoint with Endpoint::builder. You can run it next to the default DNS address lookup, or build from presets::Minimal to use only the DHT. 
use iroh::{Endpoint, endpoint::presets};
use iroh_mainline_address_lookup::DhtAddressLookup;

#[tokio::main]
async fn main() -> anyhow::Result<()> {
    let endpoint = Endpoint::builder(presets::N0)
        .address_lookup(DhtAddressLookup::builder())
        .bind()
        .await?;
    // your code here
    Ok(())
}
DHT address lookup also combines well with mDNS address lookup for both global and local address lookup without depending on centralized infrastructure. For the record format shared with DNS address lookup, see the Address Lookup concept page.