Asymmetric routing resolutions in multi-regional large scale deployments with distributed gateways

A non-transitory machine readable medium storing a program for execution by a set of processing units, the program for providing asymmetric route resolutions in an SD-WAN (software-defined wide area network), the program comprising sets of instructions for:

• at a first edge router located at a first site in a first region connected by the SD-WAN, the first edge router being one of a plurality of edge routers located at a plurality of sites across a plurality of regions connected by the SD-WAN:
• from a first hub router of a first hub router cluster, receiving a first packet flow originating from a second edge router located at a second site in a second region connected by the SD-WAN, the first packet flow sent by the second edge router via a first route that points to a second hub router of a second hub router cluster as a next hop;
• identifying a second route that is defined as a default route for reaching the second edge router from the first edge router, the second route pointing to a third hub router of the second hub router cluster as a next hop for reaching the second edge router;
• determining (i) that the first route is comprised of secure overlay tunnels between the second edge router and the first edge router and (ii) that a source network address associated with the first packet flow matches a source network address associated with the first route;
• and
• based on said determining, using the first route to send a return second packet flow to the second edge router to ensure symmetric routing.