MonoBehaviour.OnPlayerConnected(NetworkPlayer)

Description

Called on the server whenever a new player has successfully connected.

using UnityEngine;
using System.Collections;

public class ExampleClass : MonoBehaviour {
    private int playerCount = 0;
    void OnPlayerConnected(NetworkPlayer player) {
        Debug.Log("Player " + playerCount + " connected from " + player.ipAddress + ":" + player.port);
    }
}