Traps

The agent may generate asynchronous event notifications called traps. For example, if an interface adapter fails, the kernel may detect this and cause the agent to generate a trap to indicate the link is down (in some implementations, the agent may detect the condition).

Also, other applications may generate traps. For example, in addition to the gated request types shown in the Agent Function figure (Figure 1), the gated daemon generates an egpNeighborLoss trap whenever it puts an Exterior Gateway Protocol (EGP) neighbor into the down state. The agent itself generates traps (coldStart, warmStart) when it initializes and when authentication fails (authenticationFailure). Each agent has a list of hosts to which traps should be sent. The hosts are assumed to be listening on well-known port 162 for trap packets. For more information on EGP, see Exterior Gateway Protocol.