Swarm dial returns ok even if peer is not accessible

[haider-rs]

Hey i tried to dial a random multiaddr which is not accessible. but if I write it in swam dial it returns Ok

rust code:

use libp2p::{Swarm, core::transport::dummy::DummyTransport, swarm::DummyBehaviour, PeerId, Transport, Multiaddr};

fn main() {
    let mut swarm = Swarm::new(
        DummyTransport::new().boxed(),
        DummyBehaviour::default(),
        PeerId::random(),
    );

    // Dial an unknown peer.
    if let Ok(_) = swarm.dial("/ip4/100.24.100.100/tcp/1234".parse::<Multiaddr>().unwrap()){
        println!("dialed");
    }else{
        println!("error dialing");
    }
}

Output:
dialed

libp2p-lookup:
libp2p-lookup direct --address /ip4/100.24.100.100/tcp/1234
Output:
[2022-08-24T12:43:43Z ERROR libp2p_lookup] Lookup failed: Timeout.

Is this the expected behavior?
If so can I please know the responsibility of swarm dialing?
and is there any way I can check connectivity using some other function?
I know Ping but it returns an event and I want to check this before starting network loop.

Thanks

[thomaseizinger]

dial is asynchronous and only some pre-conditions are checked synchronously. You need to poll the Swarm (via next for example) and have it make progress which will eventually yield an event that informs you whether the dial was successful.

[haider-rs]

thanks