Fix/885 update default bind address

docs/examples.circuit_relay.rst

@@ -36,12 +36,14 @@ Create a file named ``relay_node.py`` with the following content:
     from libp2p.relay.circuit_v2.transport import CircuitV2Transport
     from libp2p.relay.circuit_v2.config import RelayConfig
     from libp2p.tools.async_service import background_trio_service
+    from libp2p.utils import get_wildcard_address
 
     logging.basicConfig(level=logging.DEBUG)
     logger = logging.getLogger("relay_node")
 
     async def run_relay():
-        listen_addr = multiaddr.Multiaddr("/ip4/0.0.0.0/tcp/9000")
+        # Use wildcard address to listen on all interfaces
+        listen_addr = get_wildcard_address(9000)
         host = new_host()
 
         config = RelayConfig(
@@ -107,6 +109,7 @@ Create a file named ``destination_node.py`` with the following content:
     from libp2p.relay.circuit_v2.config import RelayConfig
     from libp2p.peer.peerinfo import info_from_p2p_addr
     from libp2p.tools.async_service import background_trio_service
+    from libp2p.utils import get_wildcard_address
 
     logging.basicConfig(level=logging.DEBUG)
     logger = logging.getLogger("destination_node")
@@ -139,7 +142,8 @@ Create a file named ``destination_node.py`` with the following content:
         Run a simple destination node that accepts connections.
         This is a simplified version that doesn't use the relay functionality.
         """
-        listen_addr = multiaddr.Multiaddr(f"/ip4/0.0.0.0/tcp/9001")
+        # Create a libp2p host - use wildcard address to listen on all interfaces
+        listen_addr = get_wildcard_address(9001)
         host = new_host()
 
         # Configure as a relay receiver (stop)
@@ -252,14 +256,15 @@ Create a file named ``source_node.py`` with the following content:
     from libp2p.peer.peerinfo import info_from_p2p_addr
     from libp2p.tools.async_service import background_trio_service
     from libp2p.relay.circuit_v2.discovery import RelayInfo
+    from libp2p.utils import get_wildcard_address
 
     # Configure logging
     logging.basicConfig(level=logging.DEBUG)
     logger = logging.getLogger("source_node")
 
     async def run_source(relay_peer_id=None, destination_peer_id=None):
-        # Create a libp2p host
-        listen_addr = multiaddr.Multiaddr("/ip4/0.0.0.0/tcp/9002")
+        # Create a libp2p host - use wildcard address to listen on all interfaces
+        listen_addr = get_wildcard_address(9002)
         host = new_host()
 
         # Configure as a relay client
@@ -428,7 +433,7 @@ Running the Example
        Relay node multiaddr: /ip4/127.0.0.1/tcp/9000/p2p/QmaUigQJ9nJERa6GaZuyfaiX91QjYwoQJ46JS3k7ys7SLx
        ==================================================
 
-       Listening on: [<Multiaddr /ip4/0.0.0.0/tcp/9000/p2p/QmaUigQJ9nJERa6GaZuyfaiX91QjYwoQJ46JS3k7ys7SLx>]
+       Listening on: [<Multiaddr /ip4/127.0.0.1/tcp/9000/p2p/QmaUigQJ9nJERa6GaZuyfaiX91QjYwoQJ46JS3k7ys7SLx>]
        Protocol service started
        Relay service started successfully
        Relay limits: RelayLimits(duration=3600, data=10485760, max_circuit_conns=8, max_reservations=4)
@@ -447,7 +452,7 @@ Running the Example
        Use this ID in the source node: QmPBr38KeQG2ibyL4fxq6yJWpfoVNCqJMHBdNyn1Qe4h5s
        ==================================================
 
-       Listening on: [<Multiaddr /ip4/0.0.0.0/tcp/9001/p2p/QmPBr38KeQG2ibyL4fxq6yJWpfoVNCqJMHBdNyn1Qe4h5s>]
+       Listening on: [<Multiaddr /ip4/127.0.0.1/tcp/9001/p2p/QmPBr38KeQG2ibyL4fxq6yJWpfoVNCqJMHBdNyn1Qe4h5s>]
        Registered echo protocol handler
        Protocol service started
        Transport created
@@ -469,7 +474,7 @@ Running the Example
 
        $ python source_node.py
        Source node started with ID: QmPyM56cgmFoHTgvMgGfDWRdVRQznmxCDDDg2dJ8ygVXj3
-       Listening on: [<Multiaddr /ip4/0.0.0.0/tcp/9002/p2p/QmPyM56cgmFoHTgvMgGfDWRdVRQznmxCDDDg2dJ8ygVXj3>]
+       Listening on: [<Multiaddr /ip4/127.0.0.1/tcp/9002/p2p/QmPyM56cgmFoHTgvMgGfDWRdVRQznmxCDDDg2dJ8ygVXj3>]
        Protocol service started
        No relay peer ID provided. Please enter the relay\'s peer ID:
        Enter relay peer ID: QmaUigQJ9nJERa6GaZuyfaiX91QjYwoQJ46JS3k7ys7SLx

docs/examples.identify.rst

@@ -12,7 +12,7 @@ This example demonstrates how to use the libp2p ``identify`` protocol.
     $ identify-demo
     First host listening. Run this from another console:
 
-    identify-demo -p 8889 -d /ip4/0.0.0.0/tcp/8888/p2p/QmUiN4R3fNrCoQugGgmmb3v35neMEjKFNrsbNGVDsRHWpM
+    identify-demo -p 8889 -d /ip4/127.0.0.1/tcp/8888/p2p/QmUiN4R3fNrCoQugGgmmb3v35neMEjKFNrsbNGVDsRHWpM
 
     Waiting for incoming identify request...
 
@@ -21,13 +21,13 @@ folder and paste it in:
 
 .. code-block:: console
 
-    $ identify-demo -p 8889 -d /ip4/0.0.0.0/tcp/8888/p2p/QmUiN4R3fNrCoQugGgmmb3v35neMEjKFNrsbNGVDsRHWpM
-    dialer (host_b) listening on /ip4/0.0.0.0/tcp/8889
+    $ identify-demo -p 8889 -d /ip4/127.0.0.1/tcp/8888/p2p/QmUiN4R3fNrCoQugGgmmb3v35neMEjKFNrsbNGVDsRHWpM
+    dialer (host_b) listening on /ip4/127.0.0.1/tcp/8889
     Second host connecting to peer: QmUiN4R3fNrCoQugGgmmb3v35neMEjKFNrsbNGVDsRHWpM
     Starting identify protocol...
     Identify response:
     Public Key (Base64): CAASpgIwggEiMA0GCSqGSIb3DQEBAQUAA4IBDwAwggEKAoIBAQDC6c/oNPP9X13NDQ3Xrlp3zOj+ErXIWb/A4JGwWchiDBwMhMslEX3ct8CqI0BqUYKuwdFjowqqopOJ3cS2MlqtGaiP6Dg9bvGqSDoD37BpNaRVNcebRxtB0nam9SQy3PYLbHAmz0vR4ToSiL9OLRORnGOxCtHBuR8ZZ5vS0JEni8eQMpNa7IuXwyStnuty/QjugOZudBNgYSr8+9gH722KTjput5IRL7BrpIdd4HNXGVRm4b9BjNowvHu404x3a/ifeNblpy/FbYyFJEW0looygKF7hpRHhRbRKIDZt2BqOfT1sFkbqsHE85oY859+VMzP61YELgvGwai2r7KcjkW/AgMBAAE=
-    Listen Addresses: ['/ip4/0.0.0.0/tcp/8888/p2p/QmUiN4R3fNrCoQugGgmmb3v35neMEjKFNrsbNGVDsRHWpM']
+    Listen Addresses: ['/ip4/127.0.0.1/tcp/8888/p2p/QmUiN4R3fNrCoQugGgmmb3v35neMEjKFNrsbNGVDsRHWpM']
     Protocols: ['/ipfs/id/1.0.0', '/ipfs/ping/1.0.0']
     Observed Address: ['/ip4/127.0.0.1/tcp/38082']
     Protocol Version: ipfs/0.1.0

docs/examples.identify_push.rst

@@ -34,11 +34,11 @@ There is also a more interactive version of the example which runs as separate l
     ==== Starting Identify-Push Listener on port 8888 ====
 
     Listener host ready!
-    Listening on: /ip4/0.0.0.0/tcp/8888/p2p/QmUiN4R3fNrCoQugGgmmb3v35neMEjKFNrsbNGVDsRHWpM
+    Listening on: /ip4/127.0.0.1/tcp/8888/p2p/QmUiN4R3fNrCoQugGgmmb3v35neMEjKFNrsbNGVDsRHWpM
     Peer ID: QmUiN4R3fNrCoQugGgmmb3v35neMEjKFNrsbNGVDsRHWpM
 
     Run dialer with command:
-    identify-push-listener-dialer-demo -d /ip4/0.0.0.0/tcp/8888/p2p/QmUiN4R3fNrCoQugGgmmb3v35neMEjKFNrsbNGVDsRHWpM
+    identify-push-listener-dialer-demo -d /ip4/127.0.0.1/tcp/8888/p2p/QmUiN4R3fNrCoQugGgmmb3v35neMEjKFNrsbNGVDsRHWpM
 
     Waiting for incoming connections... (Ctrl+C to exit)
 
@@ -47,12 +47,12 @@ folder and paste it in:
 
 .. code-block:: console
 
-    $ identify-push-listener-dialer-demo -d /ip4/0.0.0.0/tcp/8888/p2p/QmUiN4R3fNrCoQugGgmmb3v35neMEjKFNrsbNGVDsRHWpM
+    $ identify-push-listener-dialer-demo -d /ip4/127.0.0.1/tcp/8888/p2p/QmUiN4R3fNrCoQugGgmmb3v35neMEjKFNrsbNGVDsRHWpM
 
     ==== Starting Identify-Push Dialer on port 8889 ====
 
     Dialer host ready!
-    Listening on: /ip4/0.0.0.0/tcp/8889/p2p/QmZyXwVuTaBcDeRsSkJpOpWrSt
+    Listening on: /ip4/127.0.0.1/tcp/8889/p2p/QmZyXwVuTaBcDeRsSkJpOpWrSt
 
     Connecting to peer: QmUiN4R3fNrCoQugGgmmb3v35neMEjKFNrsbNGVDsRHWpM
     Successfully connected to listener!

docs/examples.pubsub.rst

@@ -15,7 +15,7 @@ This example demonstrates how to create a chat application using libp2p's PubSub
     2025-04-06 23:59:17,471 - pubsub-demo - INFO - Your selected topic is: pubsub-chat
     2025-04-06 23:59:17,472 - pubsub-demo - INFO - Using random available port: 33269
     2025-04-06 23:59:17,490 - pubsub-demo - INFO - Node started with peer ID: QmcJnocH1d1tz3Zp4MotVDjNfNFawXHw2dpB9tMYGTXJp7
-    2025-04-06 23:59:17,490 - pubsub-demo - INFO - Listening on: /ip4/0.0.0.0/tcp/33269
+    2025-04-06 23:59:17,490 - pubsub-demo - INFO - Listening on: /ip4/127.0.0.1/tcp/33269
     2025-04-06 23:59:17,490 - pubsub-demo - INFO - Initializing PubSub and GossipSub...
     2025-04-06 23:59:17,491 - pubsub-demo - INFO - Pubsub and GossipSub services started.
     2025-04-06 23:59:17,491 - pubsub-demo - INFO - Pubsub ready.
@@ -35,7 +35,7 @@ Copy the line that starts with ``pubsub-demo -d``, open a new terminal and paste
     2025-04-07 00:00:59,846 - pubsub-demo - INFO - Your selected topic is: pubsub-chat
     2025-04-07 00:00:59,846 - pubsub-demo - INFO - Using random available port: 51977
     2025-04-07 00:00:59,864 - pubsub-demo - INFO - Node started with peer ID: QmYQKCm95Ut1aXsjHmWVYqdaVbno1eKTYC8KbEVjqUaKaQ
-    2025-04-07 00:00:59,864 - pubsub-demo - INFO - Listening on: /ip4/0.0.0.0/tcp/51977
+    2025-04-07 00:00:59,864 - pubsub-demo - INFO - Listening on: /ip4/127.0.0.1/tcp/51977
     2025-04-07 00:00:59,864 - pubsub-demo - INFO - Initializing PubSub and GossipSub...
     2025-04-07 00:00:59,864 - pubsub-demo - INFO - Pubsub and GossipSub services started.
     2025-04-07 00:00:59,865 - pubsub-demo - INFO - Pubsub ready.

docs/examples.random_walk.rst

@@ -23,7 +23,7 @@ The Random Walk implementation performs the following key operations:
     2025-08-12 19:51:25,424 - random-walk-example - INFO - Mode: server, Port: 0 Demo interval: 30s
     2025-08-12 19:51:25,426 - random-walk-example - INFO - Starting server node on port 45123
     2025-08-12 19:51:25,426 - random-walk-example - INFO - Node peer ID: 16Uiu2HAm7EsNv5vvjPAehGAVfChjYjD63ZHyWogQRdzntSbAg9ef
-    2025-08-12 19:51:25,426 - random-walk-example - INFO - Node address: /ip4/0.0.0.0/tcp/45123/p2p/16Uiu2HAm7EsNv5vvjPAehGAVfChjYjD63ZHyWogQRdzntSbAg9ef
+    2025-08-12 19:51:25,426 - random-walk-example - INFO - Node address: /ip4/127.0.0.1/tcp/45123/p2p/16Uiu2HAm7EsNv5vvjPAehGAVfChjYjD63ZHyWogQRdzntSbAg9ef
     2025-08-12 19:51:25,427 - random-walk-example - INFO - Initial routing table size: 0
     2025-08-12 19:51:25,427 - random-walk-example - INFO - DHT service started in SERVER mode
     2025-08-12 19:51:25,430 - libp2p.discovery.random_walk.rt_refresh_manager - INFO - RT Refresh Manager started

examples/advanced/network_discover.py

@@ -14,11 +14,26 @@
         expand_wildcard_address,
         get_available_interfaces,
         get_optimal_binding_address,
+        get_wildcard_address,
     )
 except ImportError:
-    # Fallbacks if utilities are missing
+    # Fallbacks if utilities are missing - use minimal network discovery
+    import socket
+
     def get_available_interfaces(port: int, protocol: str = "tcp"):
-        return [Multiaddr(f"/ip4/0.0.0.0/{protocol}/{port}")]
+        # Try to get local network interfaces, fallback to loopback
+        addrs = []
+        try:
+            # Get hostname IP (better than hardcoded localhost)
+            hostname = socket.gethostname()
+            local_ip = socket.gethostbyname(hostname)
+            if local_ip != "127.0.0.1":
+                addrs.append(Multiaddr(f"/ip4/{local_ip}/{protocol}/{port}"))
+        except Exception:
+            pass
+        # Always include loopback as fallback
+        addrs.append(Multiaddr(f"/ip4/127.0.0.1/{protocol}/{port}"))
+        return addrs
 
     def expand_wildcard_address(addr: Multiaddr, port: int | None = None):
         if port is None:
@@ -27,6 +42,15 @@ def expand_wildcard_address(addr: Multiaddr, port: int | None = None):
         return [Multiaddr(addr_str + f"/{port}")]
 
     def get_optimal_binding_address(port: int, protocol: str = "tcp"):
+        # Try to get a non-loopback address first
+        interfaces = get_available_interfaces(port, protocol)
+        for addr in interfaces:
+            if "127.0.0.1" not in str(addr):
+                return addr
+        # Fallback to loopback if no other interfaces found
+        return Multiaddr(f"/ip4/127.0.0.1/{protocol}/{port}")
+
+    def get_wildcard_address(port: int, protocol: str = "tcp"):
         return Multiaddr(f"/ip4/0.0.0.0/{protocol}/{port}")
 
 
@@ -37,7 +61,10 @@ def main() -> None:
     for a in interfaces:
         print(f"  - {a}")
 
-    wildcard_v4 = Multiaddr(f"/ip4/0.0.0.0/tcp/{port}")
+    # Demonstrate wildcard address as a feature
+    wildcard_v4 = get_wildcard_address(port)
+    print(f"\nWildcard address (feature): {wildcard_v4}")
+
     expanded_v4 = expand_wildcard_address(wildcard_v4)
     print("\nExpanded IPv4 wildcard:")
     for a in expanded_v4:

examples/bootstrap/bootstrap.py

@@ -2,7 +2,6 @@
 import logging
 import secrets
 
-import multiaddr
 import trio
 
 from libp2p import new_host
@@ -54,18 +53,26 @@ def on_peer_discovery(peer_info: PeerInfo) -> None:
 
 async def run(port: int, bootstrap_addrs: list[str]) -> None:
     """Run the bootstrap discovery example."""
+    from libp2p.utils.address_validation import (
+        find_free_port,
+        get_available_interfaces,
+        get_optimal_binding_address,
+    )
+
+    if port <= 0:
+        port = find_free_port()
+
     # Generate key pair
     secret = secrets.token_bytes(32)
     key_pair = create_new_key_pair(secret)
 
-    # Create listen address
-    listen_addr = multiaddr.Multiaddr(f"/ip4/0.0.0.0/tcp/{port}")
+    # Create listen addresses for all available interfaces
+    listen_addrs = get_available_interfaces(port)
 
     # Register peer discovery handler
     peerDiscovery.register_peer_discovered_handler(on_peer_discovery)
 
     logger.info("🚀 Starting Bootstrap Discovery Example")
-    logger.info(f"📍 Listening on: {listen_addr}")
     logger.info(f"🌐 Bootstrap peers: {len(bootstrap_addrs)}")
 
     print("\n" + "=" * 60)
@@ -80,7 +87,22 @@ async def run(port: int, bootstrap_addrs: list[str]) -> None:
     host = new_host(key_pair=key_pair, bootstrap=bootstrap_addrs)
 
     try:
-        async with host.run(listen_addrs=[listen_addr]):
+        async with host.run(listen_addrs=listen_addrs):
+            # Get all available addresses with peer ID
+            all_addrs = host.get_addrs()
+
+            logger.info("Listener ready, listening on:")
+            print("Listener ready, listening on:")
+            for addr in all_addrs:
+                logger.info(f"{addr}")
+                print(f"{addr}")
+
+            # Display optimal address for reference
+            optimal_addr = get_optimal_binding_address(port)
+            optimal_addr_with_peer = f"{optimal_addr}/p2p/{host.get_id().to_string()}"
+            logger.info(f"Optimal address: {optimal_addr_with_peer}")
+            print(f"Optimal address: {optimal_addr_with_peer}")
+
             # Keep running and log peer discovery events
             await trio.sleep_forever()
     except KeyboardInterrupt:
@@ -98,7 +120,7 @@ def main() -> None:
     Usage:
         python bootstrap.py -p 8000
         python bootstrap.py -p 8001 --custom-bootstrap \\
-            "/ip4/127.0.0.1/tcp/8000/p2p/QmYourPeerID"
+            "/ip4/[HOST_IP]/tcp/8000/p2p/QmYourPeerID"
     """
 
     parser = argparse.ArgumentParser(

examples/chat/chat.py

@@ -1,4 +1,5 @@
 import argparse
+import logging
 import sys
 
 import multiaddr
@@ -17,6 +18,11 @@
     info_from_p2p_addr,
 )
 
+# Configure minimal logging
+logging.basicConfig(level=logging.WARNING)
+logging.getLogger("multiaddr").setLevel(logging.WARNING)
+logging.getLogger("libp2p").setLevel(logging.WARNING)
+
 PROTOCOL_ID = TProtocol("/chat/1.0.0")
 MAX_READ_LEN = 2**32 - 1
 
@@ -40,9 +46,18 @@ async def write_data(stream: INetStream) -> None:
 
 
 async def run(port: int, destination: str) -> None:
-    listen_addr = multiaddr.Multiaddr(f"/ip4/0.0.0.0/tcp/{port}")
+    from libp2p.utils.address_validation import (
+        find_free_port,
+        get_available_interfaces,
+        get_optimal_binding_address,
+    )
+
+    if port <= 0:
+        port = find_free_port()
+
+    listen_addrs = get_available_interfaces(port)
     host = new_host()
-    async with host.run(listen_addrs=[listen_addr]), trio.open_nursery() as nursery:
+    async with host.run(listen_addrs=listen_addrs), trio.open_nursery() as nursery:
         # Start the peer-store cleanup task
         nursery.start_soon(host.get_peerstore().start_cleanup_task, 60)
 
@@ -54,10 +69,19 @@ async def stream_handler(stream: INetStream) -> None:
 
             host.set_stream_handler(PROTOCOL_ID, stream_handler)
 
+            # Get all available addresses with peer ID
+            all_addrs = host.get_addrs()
+
+            print("Listener ready, listening on:\n")
+            for addr in all_addrs:
+                print(f"{addr}")
+
+            # Use optimal address for the client command
+            optimal_addr = get_optimal_binding_address(port)
+            optimal_addr_with_peer = f"{optimal_addr}/p2p/{host.get_id().to_string()}"
             print(
-                "Run this from the same folder in another console:\n\n"
-                f"chat-demo "
-                f"-d {host.get_addrs()[0]}\n"
+                f"\nRun this from the same folder in another console:\n\n"
+                f"chat-demo -d {optimal_addr_with_peer}\n"
             )
             print("Waiting for incoming connection...")
 
@@ -86,7 +110,7 @@ def main() -> None:
     where <DESTINATION> is the multiaddress of the previous listener host.
     """
     example_maddr = (
-        "/ip4/127.0.0.1/tcp/8000/p2p/QmQn4SwGkDZKkUEpBRBvTmheQycxAHJUNmVEnjA2v1qe8Q"
+        "/ip4/[HOST_IP]/tcp/8000/p2p/QmQn4SwGkDZKkUEpBRBvTmheQycxAHJUNmVEnjA2v1qe8Q"
     )
     parser = argparse.ArgumentParser(description=description)
     parser.add_argument("-p", "--port", default=0, type=int, help="source port number")