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Cisco ONS 15530 Configuration Guide and Command Reference
78-14227-01, Cisco IOS Release 12.1(10)E2
AppendixA Command Reference
SNMP Commands
Command History
Usage Guidelines SNMP notifications can be sent as traps or inform requests. Traps are unreliable because the receiver
does not send acknowledgments when it receives traps. The sender cannot determine if the traps were
received. However, an SNMP entity that receives an inform request acknowledges the message with an
SNMP response PDU. If the sender never receives the response, the inform request can be sent again.
Thus, informs are more likely to reach their intended destination.
However, informs consume more resources in the agent and in the network. Unlike a trap, which is
discarded as soon as it is sent, an inform request is held in memory until a response is received or the
request times out. Also, traps are sent only once, while an inform might be retried several times. The
retries increase traffic and contribute to a higher overhead on the network.
If you do not enter an snmp-server host command, no notifications are sent. To configure the system to
send SNMP notifications, you must enter at least one snmp-server host command. If you enter the
command with no keywords, all trap types are enabled for the host.
To enable multiple hosts, you must issue a separate snmp-server host command for each host. You can
specify multiple notification types in the command for each host.
When multiple snmp-server host commands are given for the same host and kind of notification (trap
or inform), each succeeding command overwrites the previous command. Only the last snmp-server
host command will be in effect. For example, if you enter an snmp-server host command to enable
informs for a host and then enter another snmp-server host command to enable informs for the same
host, the second command will replace the first.
The snmp-server host command is used in conjunction with the snmp-se rver ena ble comm and . Use
the snmp-server enable command to specify which SNMP notifications are sent globally. For a host to
receive most notifications, at least one snmp-server enable command and the snmp-server host
command for that host must be enabled.
Some notification types cannot be controlled with the snmp-server enab le co mman d. Cert ain
notification types are always enabled. Other notification types are enabled by a different com mand . F or
example, the linkUpDown notifications are controlled by th e snmp trap link-status command. These
notification types do not require an snmp-server enable command.
Examples The following example shows how to enable SNMP trap notifications for APS activity.
Switch# configure terminal
Switch(config)# snmp-server host node1 traps
Related Commands
Release Modification
12.1(10)EV2 This command was introduced.
Command Description
show running-config Displays the configuration information currently running on the
system.
show snmp Displays the status of SNMP communications.
snmp-server enable traps aps Enables SNMP trap notification for APS activity.
snmp-server enable traps cdl Enables SNMP trap notification for in-band message channel
activity.