[110:103] Command execution on client failed! clinet name : Connection refused

dear all ,

when i want to update the agent on the client or add component from data protector server

i see this erro : 

[Normal]  Starting installation session on Wednesday, September 10, 2014, 2:53:50 AM...

[Normal]  Getting list of clients for installation...

[Normal]  Connecting to client 172.29.213.100...

[Normal] <172.29.213.100>  Checking for response from system 172.29.213.100.

[Normal]  Client 172.29.213.100 (Linux 2.6.18-164.el5xen) OK.

[Normal] <172.29.213.100>  Starting installation/update for client system 172.29.213.100 at Wednesday, September 10, 2014, 2:53:51 AM.

[Normal] <172.29.213.100>  Updating Core Component

[Warning] <172.29.213.100>  Update of Core Component failed!
    172.29.213.100: Connection refused


[Normal] <172.29.213.100>  Updating Disk Agent

[Warning] <172.29.213.100>  Trying an alternative path.

[Warning] <172.29.213.100>  Update of Disk Agent failed!
    

[Warning] <172.29.213.100>  [110:103] Command execution on client failed!
    172.29.213.100: Connection refused


[Normal] <172.29.213.100>  Update of client system 172.29.213.100 completed.

[Normal]  Installation session finished on Wednesday, September 10, 2014, 2:55:55 AM.


============================================================================
                      Session completed successfully!
============================================================================

dataprotector 6.11  on  win server 2003  and the client linux os

any  one can help me