Cisco IOS Cookbook, 2nd Edition

Setting SNMP Timeout Values

Problem

You want to adjust the SNMP trap timeout value.

Solution

You can use the following configuration command to adjust a router’s SNMP trap timeout value:

Router#configure terminal 
Enter configuration commands, one per line.  End with CNTL/Z.
Router(config)#snmp-server trap-timeout 60
Router(config)#end
Router#

To adjust a router’s SNMP inform timeout value, use the follow configuration commands:

Router#configure terminal 
Enter configuration commands, one per line.  End with CNTL/Z.
Router(config)#snmp-server inform timeout 120
Router(config)#end
Router#

Discussion

Before a router can send an SNMP trap, it must have a route to the destination address of the trap. If a route to the SNMP server does not exist, the router will store the trap in the retransmission queue. By default, the router will hold a trap in the retransmission queue for 30 seconds before attempting to deliver it again. Sometimes it is useful to modify the default wait time to improve the chances of successful delivery.

For instance, if the router has to send the trap over a low-speed dial backup interface, 30 seconds may not be enough time for it to trigger a call, establish connectivity, and stabilize a routing table. In a situation like this, you should consider increasing the trap timeout. The value is specified as an integer number of seconds between 1 and 1,000.

SNMP informs use timeouts differently. The inform timeout is the number of seconds that the router waits for an acknowledgement ...