ERROR: Timeout connecting to num_versions=all, retry 1/5

I'm using hosted chef, when I try to run "knife client list" or "knife cookbook list", etc. It waiting for some time and returning an error saying ;

root@node1:~/chef-repo# knife cookbook upload apache
ERROR: Timeout connecting to, retry 1/5
I'm able to ping any machine outside, and from outside to my machine as well. By the way This is my workstation machine.

What could be the problem here. ????????????