Version: 2017.3
public static bool isServer ;

説明

ピアタイプがサーバーの場合は true

using UnityEngine;
using System.Collections;

public class ExampleClass : MonoBehaviour { void OnGUI() { if (Network.isServer) GUILayout.Label("Running as a server"); else if (Network.isClient) GUILayout.Label("Running as a client"); } }