Please provide the exact steps and failure to see if we can add checks.

Deploy overcloud by passing -e ~/network-environment.yaml -e /usr/share/openstack-tripleo-heat-templates/environments/network-isolation.yaml.

/usr/share/openstack-tripleo-heat-templates/environments/network-isolation.yaml is the default

network-environment.yaml includes this compute.yaml nic template[1]. The template contains a vlan interface with IP address from StorageMgmtIpSubnet but in network-isolation.yaml compute role doesn't have a port for StorageMgmt. 

As a result this error[2] shows up on the deployed compute nodes.

[1] http://pastebin.test.redhat.com/295175
[2] http://pastebin.test.redhat.com/295181

Another check we should cover:

When creating ovs bridges only one interface should be part of the ovs bridge if bonds are not used. 

Here's an example of bad template which might lead to loops:

resources:
  OsNetConfigImpl:
    type: OS::Heat::StructuredConfig
    properties:
      group: os-apply-config
      config:
        os_net_config:
          network_config:
            -
              type: ovs_bridge
              name: br-storage
              use_dhcp: true
              members:
                -
                  type: interface
                  name: eth0
                  use_dhcp: false
                -
                  type: interface
                  name: eth1
                  use_dhcp: false
                -
                  type: interface
                  name: eth2
                  # force the MAC address of the bridge to this interface
                  primary: true
                  addresses:
                  -
                    ip_netmask: {get_param: StorageIpSubnet}
                  -
                    ip_netmask: {get_param: StorageMgmtIpSubnet}

This should be fixed with validations.