Error when ifup eth0, "Device br-ex does not seem to be present, delaying initialization."

Issue

/etc/sysconfig/network-scripts/ifcfg-br-ex was created and /etc/sysconfig/network-scripts/ifcfg-eth0 was modified to the following values but eth0 is brought up the, '/etc/sysconfig/network-scripts/ifup-eth: Device br-ex does not seem to be present, delaying initialization.' error is received.

# cat /etc/sysconfig/network-scripts/ifcfg-br-ex
DEVICE=br-ex
DEVICETYPE=ovsx
TYPE=OVSBridge
BOOTPROTO=static
IPADDR=192.168.198.100
NETMASK=255.255.255.0
GATEWAY=192.168.198.1
ONBOOT=yes

# cat /etc/sysconfig/network-scripts/ifcfg-eth0
DEVICE=eth0
HWADDR=00:00:00:00:00:FF
TYPE=OVSPort
DEVICETYPE=ovs
OVS_BRIDGE=br-ex
ONBOOT=yes