Method for dynamic load balancing in a private network comprising at least one router (R1-R8) and a plurality of access gateways (P1-P5) to an external network, each gateway providing a route to the external network and being associated with at least one domain name server operating in the transmission in the external network of data from the gateway, with the method being characterised by the following steps: - reliability test access to the external network via a reference gateway, the reliability test comprising an availability test of at least one DNS server associated with the reference gateway, - balancing on said roads and transmitting, by the router, data to the external network, based on the results of the reliability test, wherein the reliability test comprises at least one of the following steps: - emitting, by a scanning equipment of the private network, of at least one first test request to each DNS server associated with the reference gateway, wherein the route provided by the reference gateway is excluded from the balancing if the scanning equipment does not receive any response to at least one of the first test requests within a predetermined period of time, - emitting, by a scanning equipment of the private network, of a second test request to the reference gateway, wherein the route provided by the reference gateway is excluded from the balancing if the scanning equipment does not receive any response to the second test request within a predetermined period of time, - measuring a total volume of data emitted to the reference gateway in the private network and/or of a total volume of data received in the private network from the reference gateway during a predetermined period, wherein the balancing carried out by the router depends on the result of a comparison between the measured volume and a threshold volume associated with the reference gateway, and/or - measuring, by a scanning equipment of the private network, of an access bandwidth to the external network via the reference gateway, wherein the balancing carried out by the router further depends on the measured access bandwidth. - reliability test access to the external network via a reference gateway, the reliability test comprising an availability test of at least one DNS server associated with the reference gateway, - balancing on said roads and transmitting, by the router, data to the external network, based on the results of the reliability test, wherein the reliability test comprises at least one of the following steps: - emitting, by a scanning equipment of the private network, of at least one first test request to each DNS server associated with the reference gateway, wherein the route provided by the reference gateway is excluded from the balancing if the scanning equipment does not receive any response to at least one of the first test requests within a predetermined period of time, - emitting, by a scanning equipment of the private network, of a second test request to the reference gateway, wherein the route provided by the reference gateway is excluded from the balancing if the scanning equipment does not receive any response to the second test request within a predetermined period of time, - measuring a total volume of data emitted to the reference gateway in the private network and/or of a total volume of data received in the private network from the reference gateway during a predetermined period, wherein the balancing carried out by the router depends on the result of a comparison between the measured volume and a threshold volume associated with the reference gateway, and/or - measuring, by a scanning equipment of the private network, of an access bandwidth to the external network via the reference gateway, wherein the balancing carried out by the router further depends on the measured access bandwidth. - emitting, by a scanning equipment of the private network, of at least one first test request to each DNS server associated with the reference gateway, wherein the route provided by the reference gateway is excluded from the balancing if the scanning equipment does not receive any response to at least one of the first test requests within a predetermined period of time, - emitting, by a scanning equipment of the private network, of a second test request to the reference gateway, wherein the route provided by the reference gateway is excluded from the balancing if the scanning equipment does not receive any response to the second test request within a predetermined period of time, - measuring a total volume of data emitted to the reference gateway in the private network and/or of a total volume of data received in the private network from the reference gateway during a predetermined period, wherein the balancing carried out by the router depends on the result of a comparison between the measured volume and a threshold volume associated with the reference gateway, and/or - measuring, by a scanning equipment of the private network, of an access bandwidth to the external network via the reference gateway, wherein the balancing carried out by the router further depends on the measured access bandwidth.