A method performed by a device for utilizing constraint optimization for egress peer engineering to determine and implement an optimized traffic plan, the method comprising the steps of: receiving (105; 410), by the device, network data associated with a network, wherein the network includes a peer network with a plurality of network devices interconnected by links; receiving (110; 420), by the device, constraints associated with determining traffic assignments for the network; determining (115; 430), by the device, traffic and costs associated with the network based on the network data; determining (120; 440), by the device, traffic assignments for the network based on the traffic and the costs associated with the network, the constraints, and a model for the constraints, wherein the traffic assignments indicate assignments of the traffic associated with the network to one or more tunnels and peer links to be utilized for the network, and wherein the model for the constraints applies the constraints to the traffic and the costs associated with the network to determine the traffic assignments; determining (145; 450), by the device, tunnel use for the network based on the traffic assignments for the network, wherein the tunnel use indicates a quantity of tunnels to be utilized for the network; determining (150; 460), by the device, peer link use for the network based on the tunnel use for the network, wherein the peer link use indicates a quantity of peer links to be utilized for the network; determining (155; 470), by the device, costs associated with the traffic assignments, the tunnel use, and the peer link use for the network; generating (160; 480), by the device, traffic plans based on the traffic assignments, the tunnel use, the peer link use, and the costs associated with the traffic assignments, the tunnel use, and the peer link use for the network, wherein the traffic plans include information identifying the traffic assignments, the tunnel use, the peer link use, and the costs associated with the traffic assignments, the tunnel use, and the peer link use for the network; identifying, by the device, one of the traffic plans that minimizes costs associated with operating the network; and causing (170; 490), by the device, the one of the traffic plans to be implemented in the network by the plurality of network devices and the links. receiving (105; 410), by the device, network data associated with a network, wherein the network includes a peer network with a plurality of network devices interconnected by links; receiving (110; 420), by the device, constraints associated with determining traffic assignments for the network; determining (115; 430), by the device, traffic and costs associated with the network based on the network data; determining (120; 440), by the device, traffic assignments for the network based on the traffic and the costs associated with the network, the constraints, and a model for the constraints, wherein the traffic assignments indicate assignments of the traffic associated with the network to one or more tunnels and peer links to be utilized for the network, and wherein the model for the constraints applies the constraints to the traffic and the costs associated with the network to determine the traffic assignments; wherein the traffic assignments indicate assignments of the traffic associated with the network to one or more tunnels and peer links to be utilized for the network, and wherein the model for the constraints applies the constraints to the traffic and the costs associated with the network to determine the traffic assignments; determining (145; 450), by the device, tunnel use for the network based on the traffic assignments for the network, wherein the tunnel use indicates a quantity of tunnels to be utilized for the network; determining (150; 460), by the device, peer link use for the network based on the tunnel use for the network, wherein the peer link use indicates a quantity of peer links to be utilized for the network; determining (155; 470), by the device, costs associated with the traffic assignments, the tunnel use, and the peer link use for the network; generating (160; 480), by the device, traffic plans based on the traffic assignments, the tunnel use, the peer link use, and the costs associated with the traffic assignments, the tunnel use, and the peer link use for the network, wherein the traffic plans include information identifying the traffic assignments, the tunnel use, the peer link use, and the costs associated with the traffic assignments, the tunnel use, and the peer link use for the network; identifying, by the device, one of the traffic plans that minimizes costs associated with operating the network; and causing (170; 490), by the device, the one of the traffic plans to be implemented in the network by the plurality of network devices and the links.