Essential SNMP, 2nd Edition

SystemEDGE

The SystemEDGE agent is also extensible. No other system processes need to be run to extend this agent. It comes with three predefined extended objects: DNS for Unix, Network Information System (NIS) for Unix, and Remote Pinger for Unix and Windows XP, 2000, and NT. The first object returns the domain name of the underlying operating system, the second returns the NIS domain name of the underlying operating system, and the third sends Internet Control Message Protocol (ICMP) requests to a remote host from the system on which the agent is running. While these are nice scripts to have, what we want to focus on is how to add your own OIDs to the agent.

Extensibility for Unix and Windows

The SystemEDGE agent has a private MIB that defines a table called the extensionGroup. Its full OID is 1.3.6.1.4.1.546.14 (iso.org.dod.internet.private.enterprises.empire.extensionGroup). This is where you define your own objects. The first object you define has the OID extensionGroup.1.0 (1.3.6.1.4.1.546.14.1.0), where the .0 indicates that the object is scalar; the next has the OID extensionGroup.2.0, and so on. Note that all the objects defined this way must be scalar. For advanced users, Concord has developed a plug-in architecture for SystemEDGE that allows you to develop complex extended objects (including tables) and full-blown MIBs.

To extend the agent, start by editing the sysedge.cf file. This file tells the agent to which extended OIDs it must respond. The format of a command in ...