Host 5.1 on Vcenter 5.1 not responding and Vms are all disconnected

Hello

I have a server dedicated on the cloud

I have installed Vsphere 5.1

All is working fine exept when I installed a Vcenter on a VM

When I create my datacenter with my host inside, EVERY 1m25, my host is not responding and all my vms are disconnected

I have to click on the host a

and select COnnect

And again after 1m25 same issue

If I connect directly on my vsp'here nor problem

Where can I see the log is it a problem with HA I did not configure it

For your info my center is on VM Network with no card

Tks