Rmi Client - Connection refused to host: xx.xx.xxx.xx

I have 2 rmi servers that are running on 2 different machines (A and C).

The Client for these servers runs on the 3rd machine (B).

All machines have linux OS.

Machine A and B do not have a firewall between each other.  

But there is a firewall between the A and C, also there is  a firewall between B and C.


                                 Firewall    
                                      ^  
Machine A                       |          Machine C
(rmi server 1)                 |         (rmi server 2)
                                      |
                                      |
Machine B                      |
(rmi client for 1 and 2)   |


The Rmi client on machine B is successful in looking up the rmi server 1's remote interface in rmi registry on machine a which runs on port 2001 and calling the methods on it.

But, for the Machine C

1.) It takes 15-20 secs to look up the rmi object for the rmi server 2's remote interface from the rmi registry that runs on the port 2001.
2.) It gets "Connection refused to host xx.x.xxx.xx, connection timed out when calling a method on the remote object"


I am guessing it might be some permission issue. But do not know where to start. Could anyone guide me.

Any help is very much appreciated.

Thank you.