Rancher-compose external_links with alias: address not resolvable

Hi,

I read the documentation about rancher-compose and use the following format:

external_links:
    - <stack>/<service>:<alias>

I can not ping alias in the container. This results in “bad address”. I can however ping .. Using rancher 1.5.3 and rancher-compose 1.2.4.

What am I doing wrong?

Thanks,
Jeroen