As one of the key Internet protocols--like TCP/IP, UDP, SMTP and FTP--the Simple Network Management Protocol (SNMP) defines an Internet standard for monitoring and managing devices on IP networks. Such an open standard plays an important role for a widely accepted framework of Internet management, and has common support from vendors of all kinds of network devices (for example, routers, switches, local directories, firewalls, printers, modem racks, servers, and end-user hosts). With the continuing increase in network speed and the steady growth of Internet traffic, a great number of commercial and shareware applications and tools based on SNMP are available to meet the ever growing demand for the management of fixed and mobile networks.

The core feature of SNMP is given by its first term: “simple.” This feature becomes strikingly obvious when comparing SNMP with its ISO counterpart, the Common Management Information Protocol (CMIP), and is probably the main factor in SNMP’s success. The simplicity of SNMP is embodied in many of its design decisions. SNMP uses UDP rather than TCP for transporting. SNMP includes architectural components such as managers (network management stations (NMS)), agents and definitions of managed objects (Management Information Bases (MIB)). SNMP supports a small number of operations (get, set, trap, and so on). Such simplicity leads to many advantages: relatively small message size, lower performance penalties for network devices, ease of implementation and support for interoperability. Nevertheless, some weaknesses, such as lack of security, may also contribute to the “simple” of SNMP. The recent efforts in developing SNMPv2 and SNMPv3 are certainly targeted at addressing some of these shortcomings.

Essential SNMP is a practical introduction to SNMP, with a focus on explaining how SNMP works as a tool to provide network monitoring and control services. With 13 chapters and slightly more than 200 pages of text (not including six appendices), this book acts as a manual for some SNMP software tools. It contains a brief overview of SNMP architecture and some related topics (for example OIDs, MIBs, traps and community strings), system requirements (SNMP-compatible hardware and software categories), system configuration (installation and configuration of NMS and agents), operation settings (polling, setting, and traps), extensions (extensible SNMP agents) and other supports (scripts and software packages of SNMP tools). Many commercial and open source software packages that implement SNMP are explored as real cases in the book, including HP’s OpenView, Castle Rock’s SNMPc, the Net-SNMP tools, Simon Leinen’s SNMP Perl module, and MRTG (Multi Router Traffic Grapher).

As part of the legacy of O’Reilly publications, the style of this book is concise and straight talking, and the text is well written and easy to read. The many command- line examples and sample perl scripts will be an advantage to system and network administrators who have little or no experience with SNMP or SNMP applications.