Examples relates to a method for selecting headend gateway for routing subnets of branch gateways of a geographic region in a software defined wide area network (SD-WAN). In some examples, an analyzer issues a subnet to each branch gateway of a first geographic region from a pool of contiguous IP addresses, selects a first set of headend gateways suited to be assigned to the branch gateways, ranks each of the first set of headend gateways based on a parameter that includes dynamic loading of each headend gateway or link health information between each of the headend gateways and the branch gateways, and forwards the information including the ranking of headend gateways of the first set to a network orchestrator of the SD-WAN to cause the network orchestrator to assign the branch gateways to the highest ranking gateway based on information including the ranking of the first set of headend gateways.