SNMP monitoring

An object identifier (OID) represents the data points where the data for the graphs comes from. Sometimes the reason that a graph is not appearing is because the OID for the particular graph is not valid for the device. You can test this validity using the command line to see if you can return a value. To test the validity of an OID data point giving performance data:

Log in to the Control Center host as a user with serviced CLI privileges.

Attach to the Zenoss.resmgr service as the zenoss user.

serviced service attach Zenoss.resmgr su - zenoss

Run the snmpget command for one of the OIDs. For example, for a server named SERVER, enter the following command:
```
snmpget -v 2c -cpublic SERVER .1.3.6.1.4.1.2021.4.14.0
```
If the OID is valid, the snmpget command returns a value.

Basic SNMP commands

Here are some basic SNMP commands to gather certain information.

Walk a basic system MIB.

snmpwalk -v 2c -cpublic <device_name_or_ip_address> system

Walk an interface description.

snmpwalk -v 2c -cpublic <device_name_or_ip_address> ifDescr

Get a single value.

snmpget -v 2c -cpublic <device_name_or_ip_address> ifDescr.2

Detailed description of an OID value.
```
snmptranslate -Td RFC1213-MIB::ifDescr
```
Convert a name to a raw OID.
```
snmptranslate -On RFC1213-MIB::ifDescr
```
Convert a raw OID to a short name.
```
snmptranslate -OS .1.3.6.1.2.1.2.2.1.2
```