2.9.1 Functions of the native agent adapter
The native agent adapter provides an adapter function that is used to connect a native agent and an SNMP Agent instance. Using this function, you can acquire the MIB objects provided by the native agent and the MIB objects that do not belong to the system or snmp group under mib-2 via SNMP. SNMPv1 and SNMPv2c communications between the native agent adapter and native agent are addressed to the IPv4 loopback address. SNMP requests from the SNMP manager to SNMP Agent work the same way when IPv6 transport is being used.
The naa.cnf configuration file determines which MIB groups are to be acquired from the native agent. For details, see Configuration file (naa.cnf) in Chapter 6. Definition Files.
The following figure shows how the native agent adapter operates.
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- #1: The master agent binds one of the following UDP ports as the SNMP request reception port and starts:
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For Solaris and AIX: UDP port 161
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For Linux: UDP port 22161
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- #2: The native agent binds one of the following UDP ports as the SNMP request reception port and starts:
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For Solaris and AIX: UDP port 8161
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For Linux: UDP port 161
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The following describes operations when the native agent adapter starts and when SNMP requests are issued from NNM or NNMi. The numbers assigned to the operations correspond to those in Figure 2-3.
- Organization of this subsection
(1) Operations when the native agent adapter starts (indicated by the broken-line arrows)
Procedure
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The native agent adapter reads the naa.cnf definition file when it starts.
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The native agent adapter registers in the master agent the MIB objects specified in the naa.cnf definition file as the MIB objects that are to be processed by the native agent adapter.
(2) Operations when SNMP requests are issued from NNM or NNMi (indicated by the large filled arrows)
Procedure
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NNM or NNMi sends an SNMP request for the MIB object that has been defined in the naa.cnf definition file.
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The master agent distributes the MIB value operation request to the native agent adapter.
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The native agent adapter re-creates the SNMP request as an SNMP packet and sends it to the UDP port (for Solaris and AIX: 8161, for Linux: 161).
The request sent to the UDP port is received by the native agent.
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The native agent sends the SNMP response to the native agent adapter.
For the native agent, the native agent adapter functions as an SNMP manager.
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The native agent adapter returns a MIB value operation response to the master agent.
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The master agent returns an SNMP response to NNM or NNMi.
The following table lists the native agent adapter's target native agents.
OS |
Target native agent |
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Solaris |
/usr/sbin/snmpd |
AIX |
/usr/sbin/snmpd |
Linux# |
/usr/sbin/snmpd |
#: In Linux, you can select how to install the native agent. Install the native agent either by using the CD-ROM, or install it while installing OS.