Understanding SNMP implementation in Data ONTAP

SNMP process

If SNMP is enabled in Data ONTAP, SNMP managers can query the filer's SNMP agent for information (specified in the Network Appliance MIBs or the MIB-II specification). In response, the SNMP agent gathers information and forwards it to the SNMP managers using the SNMP protocol. The SNMP agent also generates trap notifications whenever specific events occur and sends these traps to the SNMP managers. The SNMP managers can then carry out actions based on information received in the trap notifications.

SNMP agent and MIB groups supported

For diagnostic and other network management services, Data ONTAP provides an SNMP agent compatible with SNMP version 1. This agent supports the MIB-II specification and the Network Appliance MIBs. The following MIB-II groups are supported:

System
Interfaces
Address translation
IP
ICMP
TCP
UDP
SNMP
Note
Transmission and EGP MIB-II groups are not supported.

For more information about protocol support, see the NetApp snmpd(8) manual page.

Types of traps in Data ONTAP

There are two types of traps in Data ONTAP:

Built-in--Built-in traps are predefined in Data ONTAP and are automatically sent to the network management stations on the traphost list if an event occurs. These traps are based on one of the following:
- RFC 1213, which defines traps such as coldStart, linkDown, linkUp, and authenticationFailure
- Specific traps defined in the Network Appliance custom MIB, such as diskFailedShutdown, cpuTooBusy, and volumeNearlyFull
For more information, see Understanding traps in Data ONTAP.
User-defined--User-defined traps exist only after they are defined by a series of snmp traps commands or the FilerView SNMP Traps windows. These traps are sent using proxy trap ID numbers 11 through 18, which correspond to a trap's MIB priority.
For more information, see Creating SNMP traps.

About the Network Appliance MIBs

A Management Information Base (MIB) file is a textual description of SNMP objects and traps. Therefore, Net App MIB files document the SNMP capabilities of the Data ONTAP version running on your filer. MIBs are not configuration files--that is, values in the MIBs are not read by Data ONTAP, and changes to the MIB files do not affect SNMP functionality.

Network Appliance provides two MIB files:

A custom MIB (/etc/mib/netapp.mib)
See Contents of the Network Appliance custom MIB.
An iSCSI MIB (/etc/mib/iscsi.mib)
SeeContents of the iSCSI MIB.

Network Appliance also provides a short cross-reference between object identifiers (OIDs) and object short names in the /etc/mib/traps.dat file. This is useful for creating user-defined traps as discussed in Defining or modifying a trap.

Note
The latest versions of the Network Appliance MIBs and traps.dat files are available online on the NetApp On the Web (NOW) site at
http://now.netapp.com/NOW/download/tools/mib/filer.shtml

However, the versions of these files on the NOW site do not necessarily correspond to the SNMP capabilities of your Data ONTAP version. They are provided to help you evaluate SNMP features in the latest Data ONTAP release.