topic Cisco ASR OTV fallback route/MAC flapping in Application Networking

topic Cisco ASR OTV fallback route/MAC flapping in Application Networking https://community.cisco.com/t5/application-networking/cisco-asr-otv-fallback-route-mac-flapping/m-p/2898977#M44016 Appreciate any advice if you have experience similar issue before. Running OTV between two sites using a pair of ASRs at each site in unicast mode. Two VLAN stretched between the two sites.  The typical behavior for MAC learn via ISIS should be admin distance of 50 with the local host MAC being 40.  When I look into it more deeply on the MAC address flapping for a handful of the hosts in one of the VLAN after a fallback test.  I see the local route towards the switch with an admin distance of 40 installed as a backup route, and a preferred alternative received from the Overlay with an admin distance of 30.   Does this mean there might be some looping occurring. Any idea what does the AD 30 mean, I can’t seem to find the definition anywhere on the web? Is there any way to ensure the locally-learned route is always preferred anyway (i.e. can I configure it to have a lower admin distance than anything the Overlay generates?)  Another strange observation is that similar routes is found in the otv arp-nd-cache for both site. Mon, 25 Apr 2016 02:43:42 GMT light101sg 2016-04-25T02:43:42Z Cisco ASR OTV fallback route/MAC flapping https://community.cisco.com/t5/application-networking/cisco-asr-otv-fallback-route-mac-flapping/m-p/2898977#M44016 Reach ability issue after OTV fallback with route/MAC flapping observed. Mon, 25 Apr 2016 02:43:42 GMT https://community.cisco.com/t5/application-networking/cisco-asr-otv-fallback-route-mac-flapping/m-p/2898977#M44016 light101sg 2016-04-25T02:43:42Z