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As The SNMP Vapors Clear
While the SNMPv3 RFCs (Requests for Comments) paint a fascinating picture of a new generation of network management using SNMP, the obvious question is: Where's the beef? At press time, SNMPv3 was a proposed standard in the IETF that already enjoyed strong support from the vendor community. Much to our surprise, several reference implementations of SNMP agents and manager software were already in prototype last spring, when we first glimpsed the SNMPv3 HotSpot at the NetWorld+Interop trade show in Las Vegas.

At N+I, SNMP Research International demonstrated not only a shipping SNMPv3 engine (its SNMP Security Pack plugs into Hewlett-Packard Co.'s Network Node Manager 5.0), but an SNMPv3 agent development toolkit and a prototype security-policy manager. In addition, several major vendors, including Bay Networks, BMC Software, Cisco Systems, Hewlett-Packard, Liebert Corp. and Tivoli Systems, displayed working prototypes of fully secure SNMPv3 agents.

A Hard Act To Follow
SNMP is the cornerstone of today's enterprise network management systems. It's an open standard that defines a way for network managers to obtain specific performance and configuration information from a software agent resident on a remote-network device. As the de facto standard for managing data networks (its OSI-based cousin, CMIP, dominates telecommunications network management), SNMP manages everything, from application-layer network services to the thousands of infrastructure devices in enterprise networks.

SNMP is a simple query/response protocol. Through an extensible dictionary of known types of device information, or MIB, SNMP is commonly used to obtain information such as the current values of packet or octet counters, status indicators and configuration parameters. The specific value of each piece of information is represented as an object in the MIB. MIBs may be IETF standards, such as MIB, MIB2, RMON or RMON2, or defined by vendor-specific extensions that must be added to SNMP managers and agents.

SNMP allows managers not only to query information about a specific MIB object, or "Get" operation, but also to change a value using a "Set" operation. SNMP also defines a reverse channel, or "Trap," where agents can send messages to a management station, usually in response to an alert.

As the foundation of complex network management frameworks such as Cabletron Systems' Spectrum, Computer Associates International's Unicenter TNG, Hewlett-Packard Co.'s Network Node Manager and Tivoli Systems' TME 10, SNMP provides a ubiquitous communications medium between management platforms and individual network devices and services.

Network-performance monitoring and baselining tools such as those from Concord Communications, DeskTalk Systems and Kaspia Systems (see "Proactive Network Management," www.networkcomputing.com/908/908f1.html) also rely on SNMP to obtain RMON and RMON2 information from remote network probes.

While the majority of network management today still relies on the original SNMPv1 specification, some products, such as HP's Network Node Manager, include support for SNMPv2c.