RBF : refreshServiceAcl command fail with router

namenode> ./bin/hdfs dfsadmin -refreshServiceAcl
Refresh service acl failed for host:8888
Refresh service acl failed for host:8888
refreshServiceAcl: 2 exceptions [org.apache.hadoop.ipc.RemoteException(org.apache.hadoop.ipc.RpcNoSuchProtocolException): Unknown protocol: org.apache.hadoop.security.authorize.RefreshAuthorizationPolicyProtocol
        at org.apache.hadoop.ipc.ProtobufRpcEngine$Server$ProtoBufRpcInvoker.getProtocolImpl(ProtobufRpcEngine.java:444)
        at org.apache.hadoop.ipc.ProtobufRpcEngine$Server$ProtoBufRpcInvoker.call(ProtobufRpcEngine.java:502)
        at org.apache.hadoop.ipc.RPC$Server.call(RPC.java:991)
        at org.apache.hadoop.ipc.Server$RpcCall.run(Server.java:878)
        at org.apache.hadoop.ipc.Server$RpcCall.run(Server.java:824)
        at java.security.AccessController.doPrivileged(Native Method)
        at javax.security.auth.Subject.doAs(Subject.java:422)
        at org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1729)
        at org.apache.hadoop.ipc.Server$Handler.run(Server.java:2684)
, java.net.ConnectException: Call From host1 to host2:8888 failed on connection exception: java.net.ConnectException: Connection refused; For more details see:  http://wiki.apache.org/hadoop/ConnectionRefused]
namenode>