Implementation of new network services and/or protocols or even change of the rules the network is used by, acts as a challenge for potential aggressors. The new techniques and methods of attacks face each other with immediate response from the vendors of network security solutions. Changes and improvements introduced by them give the aggressors a boost for finding a way around. Briefly presented way from simple stateless firewalls up to sophisticated XTM appliances, shows the evolution of security solutions. Finally, the article presents expected trends for the future security threats and solutions.