src/tutorials/hole-punching: Clarify use of libp2p-lookup & server IP
//! ```
//!
//! Now let's make sure that the server is public, in other words let's make sure one can reach it
-//! through the Internet. From the dialing client:
+//! through the Internet. First, either manually replace `$RELAY_SERVER_IP` in the following
+//! commands or `export RELAY_SERVER_IP=ipaddr` with the appropriate relay server `ipaddr` in
+//! the dailing client and listening client.
+//!
+//! Now, from the dialing client:
//!
//! 1. Test that you can connect on Layer 3 (IP).
//!
//!
//! ``` bash
//! ## For IPv4
-//! libp2p-lookup direct --address /ip4/$RELAY_SERVER_IP
+//! libp2p-lookup direct --address /ip4/$RELAY_SERVER_IP/tcp/4001
//! ## For IPv6
-//! libp2p-lookup direct --address /ip6/$RELAY_SERVER_IP
+//! libp2p-lookup direct --address /ip6/$RELAY_SERVER_IP/tcp/4001
+//! ```
+//!
+//! The libp2p-lookup output should look something like:
+//!
+//! ``` bash
+//! $ libp2p-lookup direct --address /ip4/111.11.111.111/tcp/4001
+//! Lookup for peer with id PeerId("12D3KooWDpJ7As7BWAwRMfu1VU2WCqNjvq387JEYKDBj4kx6nXTN") succeeded.
+//!
+//! Protocol version: "/TODO/0.0.1"
+//! Agent version: "rust-libp2p/0.36.0"
+//! Observed address: "/ip4/22.222.222.222/tcp/39212"
+//! Listen addresses:
+//! - "/ip4/127.0.0.1/tcp/4001"
+//! - "/ip4/111.11.111.111/tcp/4001"
+//! - "/ip4/10.48.0.5/tcp/4001"
+//! - "/ip4/10.124.0.2/tcp/4001"
+//! Protocols:
+//! - "/libp2p/circuit/relay/0.2.0/hop"
+//! - "/ipfs/ping/1.0.0"
+//! - "/ipfs/id/1.0.0"
+//! - "/ipfs/id/push/1.0.0"
//! ```
//!
//! ## Setting up the listening client
