The Simple Network Management Protocol (SNMP) is an Internet-standard protocol for managing hosts on an IP network. Devices that typically support SNMP include routers, switches, servers, workstations, printers, modem racks, UPSs, and more. Essential SNMP is a practical introduction to SNMP for network and system administrators. It starts with the basics of SNMP and how it works, along with the technical background to use it effectively. The book covers OIDs, MIBs, community strings, and traps, and other technical elements. But the main focus is on practical network administration: how to configure SNMP agents and network management stations, how to use SNMP to retrieve and modify variables on network devices, how to configure management software to react to traps sent by managed devices. Essential SNMP explores both commercial and open source packages, including HP's OpenView, Castle Rock's SNMPc, the UCD SNMP tools, Simon Leinen's Perl SNMP support, and MRTG. Administrators should come away with ideas for writing scripts to help them manage their networks, create managed objects, and extend the operation of SNMP agents. In addition to SNMPv1 and v2, the book covers SNMPv3.