It is quite difficult to overcome sniffer attacks. However, the following steps can be taken as countermeasures against such attacks:
* Use encrypted protocols for all communication.
* Segment the network to limit the spread of information.
* Use switches instead of hubs since they switch communications, which means that information is delivered only to the predefined host.
* Use a sniffer detector that checks whether an NIC is in promiscuous mode or not.
* For wireless networks, reduce the range of the network so that it can cover only the necessary surface area.