mdns peerDiscovery does not trigger peer:discover event

[pcontezini]

I'm using libp2p-js and can't figure out why my two test nodes, running on two machines with different ports, can't find each other using mdns. I'm also bootstrapping with a server node, but since I'm using both peerDiscover methods, they should be able to find each other easily.

They do print each other in mdns debug logs, but the event peer discovery is never triggered for the mdns method:

libp2p:mdns peer found 12D3KooWFgSnxaTQLYg7Z9hY6WSHGwmwnHH3yGJo7jK3ELx72TPP +6s
libp2p:mdns discovered peer in mDNS query response 12D3KooWFgSnxaTQLYg7Z9hY6WSHGwmwnHH3yGJo7jK3ELx72TPP +0ms

Did anyone face the same situation?

Here is my config:

  // Common base configuration for client and server
  const baseConfig = {
      start: false,
      addresses: {
          listen: [this.multiAddr]
      },
      transports: [tcp()],
      streamMuxers: [yamux()],
      connectionEncrypters: [noise()],
      privateKey: this.privateKey,
      peerStore: {
          persistence: true,
          threshold: 5
      },
      datastore: this.store,          
      services: {
          identify: identify({
              agentVersion: "xxxxx"
          }),
          identifyPush: identifyPush(),
          ping: ping(),
          pubsub: gossipsub()
      }
  };

  // Server-specific configurations
  const serverConfig = {
      addresses: {
          ...baseConfig.addresses,
          announce: [announceInfo]
      },
      connectionManager: {
          maxConnections: Infinity,
          minConnections: 50
      },
      services: {
          ...baseConfig.services,
          kadDHT: kadDHT({
              clientMode: false,
              kBucketSize: 20
          }),
          uPnPNAT: uPnPNAT({
              autoConfirmAddress: true
          })
      }
  };

  // Client-specific configurations
  const clientConfig = {
      peerDiscovery: [
          bootstrap({
              list: this.params.nodes ? this.params.nodes : bootstrappers
          }),
          mdns(),
      ],
      connectionManager: {
          maxConnections: Infinity,
          //minConnections: 2,
          autoDialInterval: 30000
      },
      services: {
          ...baseConfig.services,
          kadDHT: kadDHT({
              clientMode: true,
              allowQueryWithZeroPeers: true,
              kBucketSize: 20,
              randomWalk: {
                  enabled: true
              }
          }),
          uPnPNAT: uPnPNAT({
            autoConfirmAddress: true
          }),
          keychain: keychain()
      }
  };

  // Merge configurations
  const finalConfig = {
      ...baseConfig,
      ...(this.params.p2p_server ? serverConfig : clientConfig)
  };

  debug(`libp2p running in ${this.params.p2p_server ? 'SERVER' : 'CLIENT'} mode`);
  this.node = await createLibp2p(finalConfig);

  this.node.addEventListener('peer:discovery', (evt) => {
    const peerInfo = evt.detail
    debug('[peer:discovery] Discovered:', peerInfo.id.toString());
    debug(peerInfo.toString());
  });

[dozyio]

Does this minimal example work for you?

import { createLibp2p } from 'libp2p'
import { tcp } from '@libp2p/tcp'
import { mdns } from '@libp2p/mdns'
import { noise } from '@chainsafe/libp2p-noise'
import { yamux } from '@chainsafe/libp2p-yamux'

const node = await createLibp2p({
  addresses: {
    listen: ['/ip4/0.0.0.0/tcp/0']
  },
  transports: [tcp()],
  connectionEncrypters: [noise()],
  streamMuxers: [yamux()],
  peerDiscovery: [
    mdns()
  ]
})

console.log('self peer id', node.peerId)

node.addEventListener('peer:discovery', (evt) => {
  console.log('Discovered', evt.detail.id.toString(), evt.detail.multiaddrs) // Log discovered peer
})