I am trying to connect to a sqoop server on localhost:
sqoop:000> set server --host manager --port 12000 --webapp sqoop
Server is set successfully
sqoop:000> show version -all
client version:
  Sqoop 1.99.6 source revision 07244c3915975f26f03d9e1edf09ab7d06619bb8 
  Compiled by root on Wed Apr 29 10:40:43 CST 2015
0    [main] WARN  org.apache.hadoop.util.NativeCodeLoader  - Unable to load native-hadoop library for your platform... using builtin-java classes where applicable
Exception has occurred during processing command 
Exception: org.apache.sqoop.common.SqoopException Message: CLIENT_0000:An unknown error has occurred
sqoop:000> 
Port 12000 is closed
    $ netstat -na|grep 12000 
Why is this happening?