Adaptive traffic routing in a software-defined wide area network

A networking device, comprising:

• processing circuitry;
• and
• memory including instructions that, when executed by the processing circuitry, cause the networking device to:
• receive, from a branch gateway (BG), an indication that the BG has joined a wide area network (WAN);
• assign, based in part on first load information of a first virtual internet gateway (VIG) and second load information of a second VIG, the first VIG as a primary VIG for the BG;
• transmit, to the first VIG, a first redistribution cost;
• and
• transmit, to the second VIG, a second redistribution cost greater than the first redistribution cost;
• receive, from a second BG, an indication that the second BG has joined the WAN;
• assign, based in part on the first load information and the second load information, the second VIG as a primary VIG for the second BG;
• transmit, to the second VIG, a third redistribution cost;
• and
• transmit, to the first VIG, a fourth redistribution cost greater than the third redistribution cost;
• and
• assign the first VIG as a secondary VIG for the second BG, wherein a third route passes between the second VIG and the second BG, and a fourth route passes between the first VIG and the second BG, and wherein the third redistribution cost and the fourth redistribution cost indicate that packets addressed to pass addressed to pass between the BG and one of the first VIG and the second VIG should preferably be routed through the second route.