Ceph

I have a big problema with my ceph cluster. I can not execute any ceph command, when I execute any ceph command, like ceph health, it is hanging until a time out happens.
I don't know what to do to solve this problema. I have tryied several commands like:
sudo systemctl ceph start
sudo systemctl ceph stopt
and so on, but the problem persist. The outputs I get when I execute ceph health command are:

monclient(hunting): authenticate timed out after 300
librados: client.admin authentication error (110) Connection timed out

Could you help me with this problem, please?

The output of the uname -a on my CentOS is:
3.10.0-327.10.1.el7.x86_64 #1 SMP Tue Feb 16 17:03:50 UTC 2016 x86_64 x86_64 x86_64 GNU/Linux

Regards