A method for determining a communication path between a first computing device and a second computing comprises: receiving, at a second computing device, a plurality of IP addresses for a first computing device; establishing a primary connection between the first and second computing devices using a first one of the plurality of IP addresses; transmitting, from the second computing device, a plurality of probe messages to each of the plurality of IP addresses; receiving, at the second computing device from the plurality of IP addresses, a plurality of responses to the plurality of probe messages; selecting one of the plurality of IP addresses for future communications between the first to the second computing device, and transferring the primary connection between the first and second computing devices to the selected IP address. Corresponding systems are also described.