The SNMP standard provides a limited number of unsolicited messages (called traps) that are sent from a device to an SNMP application. These messages can be sent by the SNMP agent on the device to notify an SNMP application of a change in status. There are six standard traps (numbered 0 through 5) as well as vendor-provided traps (6):
|
Trap # |
Trap |
Description |
|
0 |
Cold start |
The device is rebooting itself and may change its configuration or the SNMP agent's configuration. |
|
1 |
Warm start |
The device is rebooting itself but neither the device's nor the SNMP agent's configuration will change. |
|
2 |
Link down |
One of the communication links for the device is down. |
|
3 |
Link up |
One of the communication links for the device is back up. |
|
4 |
Authorization failure |
The device has received a protocol message that is not properly authenticated. |
|
5 |
EGP neighbor loss |
An EGP neighbor for which the device is an EGP peer is down and the peer relationship no longer exists. |
|
6 |
Vendor-provided traps |
The SNMP specification lets vendors define enterprise specific traps, for example a trap that occurs on a particular vendor's router. |