Java 调用master失败org.apache.hadoop.hdfs.server.datanode.datanode

在简单的双机hadoop集群中，我面临以下错误

ERROR org.apache.hadoop.hdfs.server.datanode.DataNode: java.io.IOException: Call to master/1.1.1.2:15000 failed on local exception: java.net.NoRouteToHostException: No route to host

在主机上，我的配置如下

hostname=master
in /etc/hosts
1.1.1.2 master 
1.1.1.3 node1

core-site.xml包含

<property>
<name>fs.default.name</name>
  <value>hdfs://master:15000/</value>
</property>

---

试着像这样冲水

su-c iptables-F

<property>
 <name>mapred.job.tracker</name>
 <value>master:15001</value>
</property>

In conf/master contains
master
In conf/slaves contains
master
node1

Hostname of 
node1 machine is node1 
and in /etc/hosts 
1.1.1.2 master 
1.1.1.3 node1