The "DCONFAIL" error is a result of an underlying routing issue, according to Cisco white papers, the steps outlined are: - The next hop route is not reachable - The default gateway is not installed in the RIB (Routing Information Base) - The Datagram Transport Layer Security port is not open. All of the above alludes to routing in the SD-WAN network fabric. https://www.cisco.com/c/en/us/support/docs/routers/sd-wan/214509-troubleshoot-control- connections.html#toc-hId--1851267275