Launching container on EC2 through rancher is stucked on "starting"

I have a strange problem with rancher and EC2.

I’am using rancher on private Datacenter (with an hyper-V cluster) and everything works fine. Now, I need to deploy microserevices in the cloud on EC2 virtual machines.

I create an EC2 instance, install docker (v1.11), open UDP ports 500 and 4500 …Etc I finally add this host through the Rancher UI, fine.

Now, I want to run an image from a private registry (the same I’am using on my private cluster). Rancher displays a spinner with Networking … downloading … extrating … starting … and the processus does’nt go any further. I’am stucked on starting.

But, if I connect on the same EC2 VM and if I do a “docker run …” manually it works perfectly.

How can I investigate? What should I look?

Thank you for your advices.

On more thing : If I launch a redis or an nginx container without any port mapping it works. If I launch the same with a port mapping (for example 6379:6379 for redis), it is stucked on “starting” forever without any error message.

I verified that UDP ports 500 and 4500 were opened and also HTTP 6379 for redis.

PS: I’am running rancher/agent-instance:v0.8.3 on the virtual machine