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Setting up the Annex for SNMP
CSMIM/Micro-CS Management Application Guide 18-3
Message Delivery
SNMP messages are encapsulated in UDP datagrams. The UDP layer
does not guarantee delivery. When Annex Manager transmits a
get
,
set
, or
get-next
command, the agent is expected to respond with an error message
or with the requested data. Annex Manager uses a timeout and retry
mechanism to guarantee the SNMP command’s delivery. If a timeout
occurs, Annex Manager does not know whether the command was not
received by the agent, or whether the response from the agent was lost.
The agent can also generate an unsolicited trap command and send it to
one or more network addresses. Receivers of traps do not respond to the
SNMP agent. For detailed information, please refer to
Trap Hosts and Traps
later in this chapter.
The Annex supports only the cold-start, link-up, and
link-down traps defined in MIB-II.
Setting up the Annex for SNMP
Before Annex Manager (or any other SNMP network management
application) can monitor or manage the Annex, you must define certain
configuration data, including the SNMP Community String and the
disabled_modules
and
allow_snmp_sets
parameters.
Defining the Community String
Each SNMP message contains a Community String in its header. The
receiving SNMP agent attempts to match the message’s string with an
existing Community String list. If there is no match, the SNMP agent
discards the message without responding to the sender.
Annex Manager uses one of the Community Strings defined in the Annex
configuration file. This file, which is downloaded during Annex initialization,
defines up to four Community Strings. If the file does not contain community
strings,
public
is used as a default. There is no notion of read-only or
read-write communities. For detailed information about the SNMP
Community String syntax, please refer to the
CSMIM/MicroCS
Administrator’s Guide for UNIX.