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(If you need an installation refresher, see Chapter 6, "Installing Linux Software").
That's a lot of new terms to digest in two sentences, so take a moment to look more closely.Management Information Bases (MIBs) are text definitions of each of the OID branches.Table 22-1 shows how some commonly used OIDs map to their MIB definitions.Equipment manufacturers are usually assigned their own dedicated OID branch under the enterprises MIB, and they must also provide information in universally accepted OIDs for ease of manageability.For example, NIC interface data throughput values must always be placed in a predefined location in the general tree, but a memory use value on a customized processor card may be defined in a MIB under the manufacturer's own OID branch.You must make sure that a proper backup of all your data is available.
Most servers, routers and firewalls keep their operational statistics in object identifiers (OIDs) that you can remotely retrieve via the Simple Network Management Protocol (SNMP).
As a security measure, you need to know the SNMP password, or community string, to query OIDs.
There are a number of types of community strings, the most commonly used ones are the Read Only or "get" community string that only provides access for viewing statistics and system parameters.
OIDs are arranged in a structure of management information (SMI) tree defined by the SNMP standard.
The tree starts from a root node, which then descends through branches and leaves that each add their own reference value to the path separated by a period..
This package may also require pre-requisite packages, so it is best to use an automated package updater such yum or apt to do this.