SNMP Configuration and Management Manual

Host Resources Subagent
SNMP Configuration and Management Manual—424777-006
11-22
EMS Event Messages
EMS Event Messages
Whenever the subagent behaves unexpectedly or an error condition arises, be sure to
check for EMS events that have been generated by the subagent. Described under
EMS Support on page 11-104, event messages provide information to help you
diagnose and fix problems.
Startup Problems
If the subagent stops running shortly after startup, check the EMS event log for
unusual conditions. If no EMS events explain the startup difficulty, investigate
subagent-agent communication problems.
The SNMP agent specified at subagent startup needs to be running before you start
the subagent. If the agent is not running, try to determine why. Common agent startup
problems involve security and port conflicts. To monitor port 161 (the standard SNMP
port for receiving SNMP manager requests) or any other port less than or equal to
1023, the SNMP agent must run as a process associated with the super user group
(user ID 255,n). Additionally, the port number assigned at SNMP agent startup must
not be in use by some other process, such as another SNMP agent process.
Section 2, Installing and Configuring the SNMP Agent provides complete information
on agent startup options.
You can use SCF to determine whether a SNMP agent has been started by checking
the status of the agent’s ENDPOINT OBJECT, as in the following example, where the
name of the SNMP agent process is $ZSNMP:
SCF STATUS ENDPOINT $ZSNMP.*
A properly started subagent has ENDPOINT objects with a status of STARTED.
Another common cause for startup problems is that the SNMP agent process specified
at subagent startup is already in use by another Host Resources Subagent process.
Only one Host Resources Subagent process can communicate with a particular SNMP
agent process at any time.
To determine whether a SNMP agent process name is correct, retrieve the value of
sysDescr from a manager communicating with the agent. This value, one of the
System group objects in MIB-II, includes the SNMP agent process name.
Manager Timeouts
Managers interacting with the Host Resources Subagent might experience a timeout
when:
•
The subagent cannot complete an internal system call in time.
•
The size of the MIB being maintained requires prolonged value refresh times.