SmartOS@OVH

[gemelen]

As usually, solution was simplier than I thought :)
1. Create zone with config like this:

{
  "brand": "joyent",
  ...
  "image_uuid": "87b9f4ac-5385-11e3-a304-fb868b82fe10",
  ...
  "nics": [
          {
            "physical": "net0",
            "nic_tag": "admin",
            "mac": "<virtual mac-addr>",
            "ip": "<failover-ip>",
            "netmask": "255.255.255.255",
            "gateway": "<failover-ip>",
            "primary": true
          }
  ],
  ...
}

2. zlogin and enter

   route add <server-ip three octets>.0/24 <failover-ip> -interface
   route add default <server-ip three octets>.254

3. After that our new zone is discoverable from internet.