Connectivity Guide

The numbers in boldface type show the categories and numbers that apply to Server Administrator. All Server Administrator-defined OIDs
consist of 1.3.6.1.4.1.674 followed by additional component values.
SNMP Security
SNMP version 1 has a very limited security mechanism. SNMP agents support the use of a community string, which is configured at each
SNMP agent and is passed as a part of all SNMP request messages. There is no verification that the requester is actually a member of the
specified community. As most system and network management data is not confidential, this limited security is acceptable for Get types
of requests. On the other hand, this security is not acceptable for Set types of operations where an SNMP request could power off a
system, reconfigure a redundant array of independent disks (RAID) card, and so on. Dell has chosen not to support SNMP Set operations
for this reason.
NOTE: The default SNMP agent configuration usually includes a SNMP community name such as public. For security
reasons, change the SNMP community names from their default values. For information about changing SNMP
community names, see the Dell OpenManage Server Administrator User’s Guide available on the Dell Support website at
dell.com/openmanagemanuals.
NOTE: As of iDRAC7 firmware release r1.30.30, iDRAC7 supports SNMP query operations (GET, GETNEXT, GETBULK)
via the SNMPv3 protocol, in addition to supporting query operations via the SNMP v1 and SNMP v2c protocols. More
specifically, iDRAC7 now supports the SNMP User Security Model (USM).
SNMP Traps
SNMP is frequently used to monitor systems for fault conditions such as temperature violations, hard drive failures, and so on.
Management applications can monitor for these conditions by polling the appropriate OIDs with the Get command and analyzing the
returned data. This method has its drawbacks. If it is done frequently, significant amounts of network bandwidth can be consumed. If it is
done infrequently, the response to the fault condition may not occur in a timely fashion. SNMP traps avoid these limitations of the polling
method.
An SNMP trap is an asynchronous event indicating that something significant has occurred. This is analogous to a pager receiving an
important message, except that the SNMP trap frequently contains all the information needed to diagnose a fault.
Two drawbacks to SNMP traps are that they are sent using UDP, which is not a guaranteed delivery mechanism, and that they are not
acknowledged by the receiver.
An SNMP trap message contains the trap’s enterprise OID, the agent IP address, a generic trap ID, the specific trap ID, a time stamp, and
zero or more variable bindings (varbinds). The combination of an enterprise OID and a specific trap ID uniquely identifies each Server
Administrator-defined trap. A varbind consists of an OID and its value and provides additional information about the trap.
In order for a management system to receive SNMP traps from a managed system, the node must be configured to send traps to the
management system. Trap destination configuration is dependent on the operating system. When this configuration is done, a
management application on the management system can wait for traps and act on them when received.
NOTE:
For information on Server Administrator Storage Management traps, see in Storage Management Alert
Reference, the
Alert Descriptions and Corrective Actions.
NOTE:
For the list of storage management alerts and storage management messages, see the Dell OpenManage Server
Administrator Messages Reference Guide available on the Dell Support site at dell.com/openmanagemanuals navigate to
OpenManage Software and select the version required.
14 Introduction