Test your MIB values in Linux systems

Once you've identified a value for your Linux system that you're interested in, you can register it with the Snmpwalk command. In many cases, the text file in the MIB is simply a replacement channel that refers to those "0" or "1" in the OID Directory Branch and the non-OID directory branch, where the data exists at the bottom of the leaf in extra data form. The Snmpget directive cannot be used in a directory branch that the MIB variable cannot find.

In the following example, we want to find a replacement channel for the Sscpurawuser OID, but the Snmpget directive does not find its value. This value is displayed at the sscpurawuser.0 after the snmpwalk instruction. Then Snmpget can retrieve 32-bit counter type data and its maximum value is 396271.

[Root@bigboy tmp]# snmpget-v1-c craz33guy localhost sscpurawuser " >error in Packetreason: (nosuchname) There are no such variable name in this MIB. Failed object:ucd-snmp-mib::sscpurawuser[root@bigboy tmp]# root@bigboy tmp]# snmpwalk-v1-c craz33guy localhost sscpurawuserucd-snmp-mib::sscpurawuser.0 = counter32:396241[root@bigboy tmp]# snmpget-v1-c craz33guy localhost sscpurawuser.0ucd-snmp-mib::sscpurawuser.0 = Counter32:396271[root@bigboy tmp]#

The MIB value that works under the Snmpget self is the values you can use in MRTG.

We should know that MRTG refers to the count value of the MIB as a counter value. It references the shaping data of the MIB and the gauge value in the form of a gauge value. MRTG all data is the counter value by default.

The counter value in MTRG is not displayed as a rising image, but is displayed as a change after the last query. The CPU takes up two of the counter values tracked by the MIB, and fortunately, we can display this information in the form of a percentage image by configuring the Mrtg file.

The syntactic type, the object name of the MIB, and its role is that when you configure MTRG to be the most important thing to know, we're going to explain that.

Using MIB to monitor CPU and memory

Ucd-snmp-mib MIB tracks the situation of many MIB-critical objects, and some commonly used objects are listed in the table.

Key objects in the Ucd-snmp-mib MIB

Ucd-snmp-mib Object Variable MIB type MRTG type Description sscpurawuser counter type counter

The total amount of CPU usage used by unprivileged user applications starting from system startup. The approximate value of the total CPU usage can be obtained by increasing the user, system and reasonable parameters.

Sscpurawsystem counter Type counter type the total amount of CPU usage used by the privileged user application starts at the start of the system. Sscpurawnice counter Type counter type the total amount of CPU usage used by the application of the secondary priority. Sscpurawidle Counter Type counter type

The percentage of time the CPU is unloaded from 100 subtracts this value to get a good approximation of the total CPU usage.

Memavailreal shaping standard measures the amount of physical memory available on a host

Monitoring TCP/IP protocol with MIB

The Tcp-mib MIB traces data connection information and contains some very useful objects, such as Tcpactiveopens and Tcpcurrestab. Some important objects in Tcp-mib are described in detail in the table.

Important objects in Tcp-mib MIB

Ucd-snmp-mib Object Variable MIB type MRTG type Description tcpactiveopens counter type counter type measures the number of TCP connections that have ended. The Tcpcurrestab standard metrics measure measures the number of TCP connections in a connection. Tcpinerrs counter Type counter type Total number of TCP segments with bad checksum errors