of devices -- to the extent the MIB is supported by the device vendors. SNMP MIB support is nearly universal. The CMIP also uses a MIB to know what it can and cannot request from a managed device. However, it is a more complex protocol. The original requirement that SNMP and CMIP would share the same MIB was subsequently dropped and the protocols, while retaining similarities, grew apart.

SNMP is widely supported and is commonly used for basic monitoring of network devices. A second version of SNMP (SNMPv2) has been in discussion for many years. The intention of SNMPv2 was to expand the protocol and resolve some of the shortcomings of the original. Unfortunately, because of the additions and extensions to the original SNMP, it probably should no longer be called "simple."


While MIBs describe network type of devices and the information they will make available to management protocols such as SNMP and CMIP, the Desktop Management Interface (DMI) helps solve the problem of how to manage individual desktop computers.

DMI is an agent, i.e., "a program that performs some information gathering or processing task in the background. Typically, an agent is a given a very small and well-defined task" . It runs on a PC and accesses a locally kept Management Interface File (MIF) containing descriptions of all the devices in the computer that can be managed. Hardware vendors, such as disk or network-card makers, provide information about their products that gets stored in the MIF. Management programs then make a request to DMI to retrieve the information on individual components. Because DMI provides a standard interface, management programs do not have to keep track of how to get information on a particular component -- they just need to "speak DMI." DMI gets the requested information out of the MIF and returns it to the requester. This data can be used for such things as taking inventory of workstation hardware.

DMI has also been extended to manage MIF information provided by software vendors, thereby making software part of the overall management picture.

Frameworks and Agents

System and network management are complex and ever-changing. Many tools are on the market for tackling them. Tools such as Visio Enterprise extend an existing core graphical technology to help administrators build physical or logical maps of their networks. These kinds of programs can be very helpful in tracking what exists, and where and how things are connected. In the case of Visio Enterprise, the network mapping functionality is part of a suite of related tools that help IT administrators graphically represent and manage the enterprise.

However, the larger trend in network and system management is toward the development of management frameworks. The two best known are HP's OpenView and IBM/Tivoli's Management Framework. Both include the concept of a management console or workstation used by an administrator to view and manage the network and the objects living on it -- the managed objects.

Both supply a framework in which management tools can operate. The framework provides basic services, such as a unified look and feel, a central database for storing information about managed objects and the underlying mechanism for communicating to the managed objects or to other management consoles. A vendor may develop a program to manage a new kind of high-speed communication device. Instead of having to develop a whole new standalone product, the vendor can write the management tool so it will "snap in" to the existing management framework. As a snap-in, the program can take advantage of the framework's basic services. The vendor is saved the time and expense of building an infrastructure for the tool and the end user is saved the headache of having to learn a new interface and communication scheme.

David Aden  | 
David Aden DAden@webworldtech.com is a writer from Washington, D.C.