Create a test topology with 3 Switches.
Define ECMP route with nexthop 2 VM on Switch1 and 1 VM on Switch2 & 3 each
verify the tep-state and flows :

opendaylight-user@root>tep:show
Tunnel Monitoring (for VXLAN tunnels): On
Tunnel Monitoring Interval (for VXLAN tunnels): 1000

TransportZone TunnelType SubnetMask GatewayIP VlanID DpnID IPAddress PortName
------------------------------------------------------------------------------------------------------------------------------
TZA VXLAN 88.0.0.0/24 0.0.0.0 0 3286212470853 88.0.0.7 dpdk0
TZA VXLAN 88.0.0.0/24 0.0.0.0 0 3286212470852 88.0.0.6 dpdk0
TZA VXLAN 88.0.0.0/24 0.0.0.0 0 3286212470851 88.0.0.5 dpdk0
opendaylight-user@root>tep:show-state
Tunnel Name Source-DPN Destination-DPN Source-IP Destination-IP Trunk-State Transport Type
-------------------------------------------------------------------------------------------------------------------------------------
tun404a78dd2b4 3286212470853 3286212470851 88.0.0.7 88.0.0.5 UP VXLAN
tun74cdba7e98b 3286212470851 3286212470852 88.0.0.5 88.0.0.6 UP VXLAN
tundf9f5810683 3286212470852 3286212470851 88.0.0.6 88.0.0.5 UP VXLAN
tun9c6f6b8f390 3286212470853 3286212470852 88.0.0.7 88.0.0.6 UP VXLAN
tun4f93c26e602 3286212470851 3286212470853 88.0.0.5 88.0.0.7 UP VXLAN
tun89ad015e119 3286212470852 3286212470853 88.0.0.6 88.0.0.7 UP VXLAN
opendaylight-user@root>fib-show
RD Prefix NextHop Label Origin
-------------------------------------------------------------------
100:14 10.10.1.1/32 0.0.0.0 100011 l
100:14 10.10.1.2/32 88.0.0.5 100016 l
100:14 100.100.100.100/32 88.0.0.7 100004 s
100:14 100.100.100.100/32 88.0.0.6 100004 s
100:14 100.100.100.100/32 88.0.0.5 100004 s
100:14 10.10.1.3/32 88.0.0.5 100012 l
100:14 10.10.1.7/32 88.0.0.6 100018 l
100:14 10.10.1.8/32 88.0.0.7 100013 l
100:14 10.10.1.6/32 88.0.0.6 100015 l
100:14 10.10.1.5/32 88.0.0.5 100017 l
100:14 10.10.1.4/32 88.0.0.5 100014 l
100:14 10.10.1.0/24 88.0.0.6 100010 c

======================================================
Bring down the Br-ex bridge interface of Switch3
verify the tep-state and flows

opendaylight-user@root>tep:show-state
Tunnel Name Source-DPN Destination-DPN Source-IP Destination-IP Trunk-State Transport Type
-------------------------------------------------------------------------------------------------------------------------------------
tun404a78dd2b4 3286212470853 3286212470851 88.0.0.7 88.0.0.5 UNKNOWN VXLAN
tun74cdba7e98b 3286212470851 3286212470852 88.0.0.5 88.0.0.6 UP VXLAN
tundf9f5810683 3286212470852 3286212470851 88.0.0.6 88.0.0.5 UP VXLAN
tun9c6f6b8f390 3286212470853 3286212470852 88.0.0.7 88.0.0.6 UNKNOWN VXLAN
tun4f93c26e602 3286212470851 3286212470853 88.0.0.5 88.0.0.7 DOWN VXLAN
tun89ad015e119 3286212470852 3286212470853 88.0.0.6 88.0.0.7 DOWN VXLAN
opendaylight-user@root>
opendaylight-user@root>fib-show
RD Prefix NextHop Label Origin
-------------------------------------------------------------------
100:14 10.10.1.1/32 0.0.0.0 100011 l
100:14 10.10.1.2/32 88.0.0.5 100016 l
100:14 100.100.100.100/32 88.0.0.7 100004 s
100:14 100.100.100.100/32 88.0.0.6 100004 s
100:14 100.100.100.100/32 88.0.0.5 100004 s
100:14 10.10.1.3/32 88.0.0.5 100012 l
100:14 10.10.1.7/32 88.0.0.6 100018 l
100:14 10.10.1.8/32 88.0.0.7 100013 l
100:14 10.10.1.6/32 88.0.0.6 100015 l
100:14 10.10.1.5/32 88.0.0.5 100017 l
100:14 10.10.1.4/32 88.0.0.5 100014 l
100:14 10.10.1.0/24 88.0.0.6 100010 c
opendaylight-user@root>