Supported Platforms
Related Documentation
- ACX, M, MX, PTX, T Series, QFX Series standalone switches
- Configuring SNMPv3 Traps on a Device Running Junos OS
- Minimum SNMPv3 Configuration on a Device Running Junos OS
- ACX, M, MX, PTX, T Series
- Configuring the Remote Engine and Remote User
- Configuring the Inform Notification Type and Target Address
- Complete SNMPv3 Configuration Statements
Configuring SNMP Informs
Junos OS supports two types of notifications: traps and informs. With traps, the receiver does not send any acknowledgment when it receives a trap. Therefore, the sender cannot determine if the trap was received. A trap may be lost because a problem occurred during transmission. To increase reliability, an inform is similar to a trap except that the inform is stored and retransmitted at regular intervals until one of these conditions occurs:
- The receiver (target) of the inform returns an acknowledgment to the SNMP agent.
- A specified number of unsuccessful retransmissions have been attempted and the agent discards the inform message.
If the sender never receives a response, the inform can be sent again. Thus, informs are more likely to reach their intended destination than traps are. Informs use the same communications channel as traps (same socket and port) but have different protocol data unit (PDU) types.
Informs are more reliable than traps, but they consume more network, router, and switch resources (see Figure 1). Unlike a trap, an inform is held in memory until a response is received or the timeout is reached. Also, traps are sent only once, whereas an inform may be retried several times. Use informs when it is important that the SNMP manager receive all notifications. However, if you are more concerned about network traffic, or router and switch memory, use traps.
Figure 1: Inform Request and Response
For information about configuring SNMP traps, see Configuring SNMPv3 Traps on a Device Running Junos OS.
Related Documentation
- ACX, M, MX, PTX, T Series, QFX Series standalone switches
- Configuring SNMPv3 Traps on a Device Running Junos OS
- Minimum SNMPv3 Configuration on a Device Running Junos OS
- ACX, M, MX, PTX, T Series
- Configuring the Remote Engine and Remote User
- Configuring the Inform Notification Type and Target Address
- Complete SNMPv3 Configuration Statements
Published: 2014-07-23
Supported Platforms
Related Documentation
- ACX, M, MX, PTX, T Series, QFX Series standalone switches
- Configuring SNMPv3 Traps on a Device Running Junos OS
- Minimum SNMPv3 Configuration on a Device Running Junos OS
- ACX, M, MX, PTX, T Series
- Configuring the Remote Engine and Remote User
- Configuring the Inform Notification Type and Target Address
- Complete SNMPv3 Configuration Statements
