Technological and human factors have contributed to increase the complexity of the network management problem. Heterogeneity and globalization of network resources, on one hand, have increased user expectations for flexible and easy-to-use environments; on the other hand, they have suggested entirely novel ways to face the management problem. Several research efforts recognize the need for integrated solutions to manage both network resources and services in open, global, and untrusted environments. In addition, these solutions should permit the coexistence of different management models and should interoperate with legacy systems. In the paper, we define a general architecture based on a distributed processing environment (DPE) that offers a large set of facilities to the application level. We have developed the MESIS management environment shaped after the above architecture and its DPE facilities with the mobile agents technology. MESIS handles, in a uniform way, both resources and services, and focuses on two crucial properties: interoperability to overcome heterogeneity, and security to grant users safe and protected operations. The Agent Interoperability Facility supports compliance with CORBA-based management systems and with MASIF agent platforms. The Agent Security Facility provides authentication, integrity, privacy, authorization, and secure interoperation with CORBA systems. Index Terms---Distributed systems, Internet services, interoperability, network management, security. I.

The Mobile Agent technology has already shown its advantages, but at the same time has already remarked new problems currently limiting its diffusion in commercial environments. A key issue is to control the operations that foreign mobile agents are authorized to perform on hosting execution environments. It is necessary not only to rule the MA access to resources but also to control resource usage of admitted agents at execution time, for instance to protect against possible denial-of-service attacks. The paper presents a solution framework for the on-line monitoring and control of Java-based MA platforms. In particular, it describes the design and implementation of MAPI, an on-line monitoring component that we have integrated within the SOMA system. The paper shows how to use MAPI as the building block of a distributed monitoring tool that gives application- and kernel-level information about the state of mobile agents and their resource usage, thus enabling the enforcement of management policies on MA resource consumption. 1.

Several distributed management architectures, incorporating mobile agent technology, have been recently proposed to answer the scalability limitations of centralised models and the flexibility problems of static hierarchical frameworks. Yet, although agent-based management frameworks have recently started evolving from the early ‘flat ’ models to hierarchical structures, they cannot efficiently cope with the dynamically changing traffic and topological characteristics of modern networks. This is mainly due to the limited use of agent mobility (employed either through mid-level manager entities or between static mid-level managers and managed devices) and lack of appropriate policies enabling automatic calibration of the management system based on network conditions. This paper presents a hierarchical agentbased infrastructure, suitable for the management of large-scale enterprise networks that addresses these issues. The transition to hierarchical agent-based management is achieved through a mid-level manager that being a mobile agent itself, operates at an intermediary level between the manager and the legacy systems and takes full control of managing a given network segment. These entities make the system more adaptive to changing networking conditions, while localising the traffic associated with bandwidth-intensive monitoring applications. A quantitative evaluation, in terms of the overall management cost, confirms that this architecture outperforms both centralised approaches and mobile agent-based ‘flat’ management models.

The increasing dimension and heterogeneity of global Web systems make harder their management with tools based on the client/server model. The Mobile Agent technology overcomes the limits of traditional approaches and proposes solutions that are suitable for the management of distributed and heterogeneous Internet-based systems. The paper describes the MAMAS environment and its implementation with a Mobile Agent technology. MAMAS has the goals of monitoring the whole system, introducing dynamic corrective actions and modifying system policies at run-time. MAMAS achieves these objectives by answering the guidelines of both security and compliance to standards. The choice of Java as the implementation language has permitted to achieve portability, to exploit the language security features, and to provide Web accessibility. The MAMAS compliance with CORBA ensures interoperability with legacy management platforms. Keywords: Mobile Agents, Network and Systems Management, Security, Interoperability, Web-based accessibility.

We present here a framework together with a set of paradigms for mobile agent based active monitoring of network systems. In our framework mobile agents are used to perform remote information filtering and control functions. Such agents can detect basic events or correlate existing events that are stored in a database to enforce system policies. A system administrator can securely modify the monitoring policies and information filtering functions of its agents, or install new agents at a node. The framework presented here includes monitor, subscriber, auditor and inspector agents. The policies and itineraries of these agents can be modified dynamically. In response to certain trigger events agents may change their itineraries to correlate event data. We present here a set of experiments that we have conducted using the Ajanta mobile agent system to evaluate and demonstrate the capabilities of our mobile agent framework.

The mobility of terminals and users is a crucial issue in the open global system represented by the Internet. Supporting terminal and user mobility requires a middleware infrastructure capable of efficiently answering the needs of scalable resource discovery, of security and interoperability, of Quality of Service (QoS) monitoring and adaptation. Some proposals address mobility at the network level and some others focus on application-level solutions. By following the latter approach, the paper proposes the adoption of the mobile agent technology to model and implement mobility. In particular, the paper concentrates on the components and modules implemented in the SOMA mobile agent programming framework to specifically support terminal and user mobility. The SOMA tracing and discovery system extends the SOMA basic naming service to identify and keep track of all mobile entities in the environment. The SOMA QoS adaptation support exploits the functionality of the SOMA monitoring tools and permits to dynamically adjust service provision in response to the changing network and nodes conditions. These features are integrated in a mobility add-on module that pursues also the goals of security and interoperability when moving users and roaming terminals. Keywords Mobile and Nomadic Computing, Mobile Agents, Mobile Tracing, Resource Discovery, QoS Adaptation. 1

The global scenario put together by communication networks determines new opportunities towards the realization of Internet-based distributed services in many complex and composite application areas, such as the access to museum information. Solution complexity mainly stems from the heterogeneous representation formats of data, their geographical distribution, the large number of data sources involved, and the user requirements for personal customization and optimization of the accessed services. The paper claims that the realization of flexible museum information access services require a middleware-level approach and the implementation of a distributed support infrastructure. Within the MOSAICO project, we have realized the VM (Virtual Museum) framework on top of the SOMA (Secure and Open Mobile Agent) programming environment. Mobile agents have been chosen for their intrinsic properties of autonomy, asynchronicity, dynamicity of distribution, and adaptability to available system resources. We have designed the VM to accommodate different usage scenarios: VM users can play different roles with different expertise levels; they can ask the VM infrastructure for differently complex features, from simple Web accessibility to user accounting for data resource consumption, from data customization via user profiling to automatic update of subscripted query results. The first prototype, apart from the feasibility of the approach, has already shown the potential and the flexibility of the mobile agent infrastructure to adapt to both different user requirements and different resource availability.

The technology of mobile agents has proven its usefulness for system and network management. In order to be e#ective, the integration of SNMP-based operations and the use of mobility should be e#ective.

Modern Intrusion Detection Systems (IDSs) are distributed real-time systems that detect unauthorized use or attacks upon an organization’s network and/or hosts. The components of most distributed IDSs are arranged in a hierarchical tree structure, where the sensor nodes pass information to the analyzer nodes. Optimal placement of the analyzer nodes results in an improved response time for the IDS, and isolation of attacks within the IDS network. Since the network topology and workload are constantly changing, we are able to maintain near-optimal placement of the analyzer nodes by instantiating them as mobile agents. The analyzer nodes may then relocate, reproduce or be deleted as necessary. Such flexibility improves the response times and the stability of an IDS. The movement of the analyzer nodes also offers some protection against denial-ofservice attacks, since secure analyzer nodes will be relocated to take over some of the functionality of the host under attack. KEY WORDS: intrusion detection systems; mobile agents; scalability. 1.

The increasing complexity of the network management problem is due to both technological and human factors. Heterogeneity and globalization of network resources on the one hand, increasing user expectations for flexible and easy-to-use environments on the other hand, force to consider new approaches to the management issue. In the paper, we describe MESIS (Management Environment for Secure and Interoperable Services) for the integrated management of both network resources and services. MESIS permits the design and the implementation of new services for open, global, and untrusted scenarios, such as the Internet. The principal part of MESIS is a distributed processing environment composed of a wide set of facilities that can be exploited for building services at the application layer. The paper focuses on two crucial facilities: interoperability and security. The Interoperability Facility allows MESIS services to interwork with all resources and services, even provided by legacy systems. In particular, it considers interoperability with other management systems via compliance with CORBA. The Security Facility provides to MESIS the safe and protected operations necessary in global untrusted environments. MESIS permits authentication of principals, communication integrity and privacy, accountability, and secure interoperation with CORBA-compliant systems. MESIS is implemented in terms of mobile agents, to facilitate delegation and management automation, and to achieve efficiency and scalability through local access to managed entities. 1