The increasing complexity of modern network has motivated the development of different fault detection and isolation approaches for the purpose of supervision. Currently, packet monitoring has become a standard technique in network fault detection, but when applied to a large-scale network it yields a high volume of packets. To overcome this problem, some techniques are proposed. However, the proposed techniques are based on popular SNMP agent and RMON technology, which are characterized by centralization, some inherent known problems are the lack of scalability, complexity to configure, network congestion and not strong local processing ability. This paper proposes a new method for fault detection and isolation based on intelligent mobile agents. To measure the impact on fault detection capability, a monitoring and fault detection experiment is successfully implemented, and the authors compare the number of symptoms detected and traffic of the system with a traditional system using RMON agents. Experimental results show that the fault detection capability using the proposed approach is significantly improved.