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Trap Simulator
Introduction – Trap and Inform
SNMP notifications can be sent as traps (SNMP V1) or inform requests (SNMPV2c). Traps are unreliable because the receiver does not send any acknowledgment when it receives a trap. The sender cannot determine if the trap was received. However, an SNMP manager that receives an inform request acknowledges the message with an SNMP response PDU. If the manager does not receive an inform request, it does not send a response. If the sender never receives a response, the inform request can be sent again. Thus, informs are more likely to reach their intended destination.
Because they are more reliable, informs consume more resources in the SNMP device and in the network. Unlike a trap, which is discarded as soon as it is sent, an inform request must be held in memory until a response is received or the request times out. Also, traps are sent only once, while an Inform may be retried several times. The retries increase traffic and contribute to a higher overhead on the network. Thus, traps and inform requests provide a trade-off between reliability and resources. If it is important that the SNMP manager receives every notification, use Inform requests. On the other hand, if you are concerned about traffic on your network or memory in the router and you do not need to receive every notification, use traps.
For testing LoriotPro traps filter, a useful tool, the trap simulator is provided from the version 3 update az of LoriotPro. The trap simulator generates Trap or Inform and send them to the trap receiver like the device would do.
This is very useful to test your Trap filter and check that the associated actions are well performed. It is impossible on a SNMP agent to force the generation of a Trap/Inform that is sent when a disk, a power supply a fan fails.
Starting trap simulator
To test a Trap/Inform action, select the host in the directory that you want to impersonate. From the contextual menu select: Tool and Trap Simulator.
You access the Trap Simulator Interface. Check that the address and community are right.
In the list of trap select the trap you want to simulate by a double click. The trap name is displayed in the lower text box.
The V1 list box contains only the V1 trap except the Enterprise trap (V1 type 6).
The list contain all the V1 trap (Enterprise) and V2c Inform).
Devices are not able to send all the listed Inform or Trap. You can use the SNMP walker tool to find what MIB files thus trap/inform are supported by a device.
When you have made your selection, click Send.
Come back to the LoriotPro Event Manager and select the trap tab. The trap is displayed in the trap tab window. The simulated trap has empty parameters (param1 to param10).
From there if you have defined filter associated to this trap the actions are performed.
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