# SNMP monitoring

OID represent 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:

1. Log in to the Control Center host as a user with serviced CLI privileges.
2. Attach to the Zenoss.core service.
serviced service attach Zenoss.core
3. Change to the zenoss user.
su - zenoss
4. Run the snmpget command for one of the OIDs

In this case, use the command:

\$ snmpget -v 2c -cpublic build .1.3.6.1.4.1.2021.4.14.0

where, build should be a valid server/ip address

If the OID is valid it will return a value.

Here are some basic SNMP commands to gather certain information.

1. Walk a basic system MIB.
snmpwalk -v 2c -cpublic <device_name_or_ip_address> system
2. Walk an interface description
snmpwalk -v 2c -cpublic <device_name_or_ip_address> ifDescr
3. Get a single value.
snmpget -v 2c -cpublic <device_name_or_ip_address> ifDescr.2
4. Detailed description of an OID value.
snmptranslate -Td RFC1213-MIB::ifDescr
5. Convert a name to a raw OID.
snmptranslate -On RFC1213-MIB::ifDescr
6. Convert a raw OID to a short name
snmptranslate -OS .1.3.6.1.2.1.2.2.1.2