RancherAgent loses connection with RancherServer

RancherServer: 1.6.5
RancherAgent: 1.2.5
Docker: 1.12.6
OS: Centos7 (3.10)

I am new with Rancher and I have a problem, when deploy a container or stack I see the error in container “Timeout getting Ip address” but search in the network-service stack show: no route to rancher server. I validated that ports are available and firewall rules but the problem is the same.

To resolve this, I restart docker service on server, then the network-service work fine. and the container have IP.

What is the problem that produce this error? because I don’t think restart every time that this error appear.

I appreciate your help

Best regards