Two basic strategies for implementing WBM are evolving: the proxy solution and the embedded approach. While these methodologies are not mutually exclusive, each has its advantages.
The proxy solution adds a Web-based server to an intermediate station (the proxy), which interconnects with the end devices that it manages (Figure 1). Users access the proxy through a Web browser, using the HyperText Transmission Protocol (HTTP), while the proxy accesses end devices SNMP. Usually, this approach adds a Web server to an existing management product, which optimizes functions such as database access and SNMP polling. This approach maintains the advantages of workstation-based management systems while adding flexible access to intranet data. Since the proxy communicates with all the managed devices, the administrator can view all or portions of the enterprise's networks, servers, and desktops, as well as such logical entities as virtual LANs. Since the proxy-to-device protocol remains SNMP, this approach also works with SNMP-only devices. However, the proxy technique does require a workstation.
Figure 1: The proxy solution for WBM.
The embedded method actually installs a Web server in the end device. Each device has its own Web address, and the administrator uses a Web browser to visit the managed devices (Figure 2). This approach allows graphical management of individual devices. It is a simpler interface than today's system management tools and offers easier operation with no sacrifice in functionality.
Figure 2: The embedded approach to WBM.
Many organizations will probably end up using both proxy-based and embedded Web server capabilities. Large organizations will need the enterprise-wide monitoring and management capabilities that are available only with the proxy solution. The proxy solution can also manage SNMP-only devices. In conjunction with proxy-based servers, large corporations could also benefit from embedded Web servers because of their simple setup requirements and their ability to manage new devices.
The embedded Web server approach is especially well suited for managing small branch offices. These networks are relatively simple and typically do not require powerful management systems or need enterprise-wide views. Users at these remote locations usually are not familiar with device-control and network procedures. Embedded Web servers allow these users to become operational quickly with minimal instruction. Although the plug-and-play nature of Web-based devices simplifies installation and minimizes troubleshooting, they do not necessarily limit device-level capabilities.
A Web browser can communicate directly with networked devices using HTTP. The most common reasons for connecting directly to individual network devices include configuration and reconfiguration, simple status monitoring, and implementing specific corrective actions. For small networks, this approach alone might be a sufficient management solution; for larger networks, this approach will typically supplement more global tools in a variety of circumstances, including the final stages of problem resolution.To support large-scale management, however, devices will have to continue collecting and providing remote monitoring (RMON) and multilayer topology data. Critical network devices will need these capabilities to support network systems applications.
Managing an enterprise network requires the collection and correlation of voluminous amounts of data. This type of processing is still required in order to understand and manage the network. As the era of Web-based management unfolds, more of this processing can be distributed through Java. This network processing must include such functions as correlation and presentation of network statistics, automatic baselining capabilities, and a single common point for launching all network management activities.
The technology behind these advanced management functions is the intelligent agent—software embedded in network devices that collect both RMON and RMON2 data and multilayer topology information. RMON and RMON2 data provide a detailed view of the characteristics of traffic flowing through the network, while multilayer topology information provides the management application with detailed knowledge of the physical and logical relationships between networked devices. The multilayer topology capability is important for managing a switched network, while RMON is critical to the monitoring and troubleshooting of client/server traffic.
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