Host Management Revisited (Essential SNMP)

2.7. Host Management Revisited

Managing your hosts is an important part of network management. You would think that the Host Resources MIB would be part of every host-based SNMP agent, but this isn't the case. Some SNMP agents implement this MIB, but many don't. A few agents go further and implement proprietary extensions based upon this MIB. This is mainly due to the fact that this MIB was intended to serve as a basic, watered-down framework for host management, designed mainly to foster wide deployment.

The Host Resources MIB defines the following seven groups:

host            OBJECT IDENTIFIER ::= { mib-2 25 }

hrSystem        OBJECT IDENTIFIER ::= { host 1 }
hrStorage       OBJECT IDENTIFIER ::= { host 2 }
hrDevice        OBJECT IDENTIFIER ::= { host 3 }
hrSWRun         OBJECT IDENTIFIER ::= { host 4 }
hrSWRunPerf     OBJECT IDENTIFIER ::= { host 5 }
hrSWInstalled   OBJECT IDENTIFIER ::= { host 6 }

The host OID is 1.3.6.1.2.1.25 (iso.org.dod.internet.mgmt.mib-2.host). The remaining six groups define various objects that provide information about the system.

The hrSystem (1.3.6.1.2.1.25.1) group defines objects that pertain to the system itself. These objects include uptime, system date, system users, and system processes.

The hrDevice (1.3.6.1.2.1.25.3) and hrStorage (1.3.6.1.2.1.25.2) groups define objects pertaining to filesystems and system storage, such as total system memory, disk utilization, and CPU nonidle percentage. They are particularly helpful, since they can be used to manage the disk partitions on your host. You can even use them to check for errors on a given disk device.

The hrSWRun (1.3.6.1.2.1.25.4), hrSWRunPerf (1.3.6.1.2.1.25.5), and hrSWInstalled (1.3.6.1.2.1.25.6 ) groups define objects that represent various aspects of software running or installed on the system. From these groups, you can determine what operating system is running on the host, as well as what programs the host is currently running. The hrSWInstalled group can be used to track which software packages are installed.

As you can see, the Host Resources MIB provides some necessary system-management objects that can be utilized by almost anyone who needs to manage critical systems.