我´我在namenode节点上的4节点hadoop集群中执行此命令：

hadoop fs -ls /

但它显示了一个错误：

ls: Failed on local exception: java.net.SocketException: 
Network is unreachable; Host Details: local host is "namenode/172.16.1.2"; 
destination host is: "namenode":9000;

core-site.xml文件

<configuration>
    <property>
        <name>fs.defaultFS</name>
        <value>hdfs://namenode:9000</value>
    </property>
</configuration>

cat/etc/主机：

172.16.1.2  namenode
172.16.1.3  datanode1
172.16.1.4  datanode2
172.16.1.5  datanode3