In one embodiment, a primary server receives, from a client device, a first request to mitigate an external attack on the client device. The primary server sends, to a plurality of secondary servers, a second request to mitigate the external attack, wherein each one of the plurality of secondary servers has associated mitigation resources, and receives from at least one of the plurality of secondary servers an indication that it has mitigation resources capable of mitigating the external attack. The primary server sends, to the client device, a list including the secondary servers having mitigation resources capable of mitigating the attack, and receives, from the client device, an indication that a subset of the list is selected to mitigate the external attack. In response, the primary server sends a request for mitigation services to one of the secondary servers in the subset selected to mitigate the external attack.