Circuit-relay v2 connection denied (Upgrade(Apply(NoReservation)))

[demfabris]

I'm facing problems when establishing a relayed connection using the recently implemented circuit-relay-v2

Scenario

Node A, R, and B

1. Node R starts a p2p node supporting Identify, circuit-relay-v2/hop, circuit-relay-v2/stop
   code:

$ mynode --listen 127.0.0.1 --port 4001

2. Node B starts a p2p node supporting the same behaviours and dials Node R, establishing a connection successfully.

$ mynode --listen 127.0.0.1 --port 4002
$ mynode --dial /ip4/127.0.0.1/tcp/4001/p2p/<NodeRpeerId> 

3. Node A starts a p2p node supporting the same behaviours and attempts to dial Node B via Node R as relay.

$ mynode --listen 127.0.0.1 --port 4003
$ mynode --dial /ip4/127.0.0.1/tcp/4001/p2p/<NodeRpeerId>/p2p-circuit/p2p/<NodeBpeerId>

Result

Node A establishes a connection with Node R successfully, but then a error follows in both of them:

Node R output:

ERROR_LOG: CircuitReqDenied { src_peer_id: PeerId(<nodeA>), dst_peer_id: PeerId(<nodeB>) }

Node A output:

ERROR_LOG: Behaviour(Client(OutboundCircuitReqFailed { relay_peer_id: PeerId(<nodeR>), error: Upgrade(Apply(NoReservation)) }))

ERROR_LOG: Transport([("/ip4/127.0.0.1/tcp/4001/p2p/<nodeR>/p2p-circuit/p2p/<nodeB>", Other(Custom { kind: Other, error: Other(A(A(A(A(B(Connect)))))) }))])

Node B output:
Nothing

What step I might be missing here?

[mxinden]

👋 sorry for the late reply here.

It looks like Node B does not make a reservation with R. You would need to make sure Node B listens via R, in other words that node B makes a reservation with R. Unless B has a reservation with R, R will not relay a connection from A to B.

To "listen via" R, B needs to call Swarm::listen_on with a relayed address, e.g. /ip4/127.0.0.1/tcp/4001/p2p/<NodeRpeerId>/p2p-circuit.

See example:

rust-libp2p/protocols/relay/tests/v2.rs

Lines 53 to 60 in e66f04f

	let client_addr = relay_addr
	.clone()
	.with(Protocol::P2p(relay_peer_id.into()))
	.with(Protocol::P2pCircuit);
	let mut client = build_client();
	let client_peer_id = *client.local_peer_id();
	client.listen_on(client_addr.clone()).unwrap();

Does that solve your issue @demfabris?

[demfabris]

That's exactly what I was missing 😄
This wasted me a couple of days... Not very much disclosed in the docs.

Thanks

[mxinden]

This wasted me a couple of days... Not very much disclosed in the docs.

Sorry to hear. Would you mind proposing a docs change (PR) to avoid future users running in the same issue?