EFA as SNMP Proxy

EFA acts as the SNMP Manager for all the SLX devices and agents and receives the traps from all the devices in its inventory.

Simple Network Management Protocol (SNMP) traps are alert messages sent from a remote SNMP-enabled device to a central collector, the SNMP Manager. Trap messages are the main form of communication between SNMP monitoring tools – an SNMP Agent and an SNMP Manager.

EFA acts as the SNMP Manager for all the SLX devices and agents and receives the traps from all the devices in its inventory. Once you register an SLX device with EFA, EFA automatically configures the SLX device to send v3 traps to EFA.

EFA acts as an SNMP proxy for all the SNMP v2 and v3 traps received from the SLX devices, forwarding them onto an external trap receiver, if there is one.

• EFA subscribes to be a v3 trap receiver with a predefined v3 user name, authentication key, and privacy key.
• If you set up EFA to be a v2c trap receiver, you must provide a community string.

During an update operation, EFA verifies that it is still registered to receive traps from the SLX devices. If a device is unregistered from EFA, the SNMP configuration on the device is updated to no longer send traps to the EFA IP address.

Notes

• The device IP address is the one included in SNMP-COMMUNITY-MIB::snmpTrapAddress.0. It is not the EFA IP address.
• EFA forwards all received traps. In other words, no trap is filtered out.
• Port 162 on the host where EFA is installed must be available. During a fresh installation, the port availability is checked and the installer returns an error if the port is not available. However, during an upgrade from a previous version of EFA, you must ensure that the port is free.

For more information about SLX-OS MIBs, see the Extreme SLX-OS MIB Reference for your version of SLX-OS.

Limitations

• A maximum of four trap subscribers is supported.
• V2c and v3 SNMP subscribers are not validated.
• Only traps generated by SLX devices are forwarded. Alerts and alarms from EFA itself are not forwarded.
• Only traps are forwarded. Current EFA tasks or alerts and syslog messages are not forwarded as traps.
• SNMP Informs are not supported.
• There is no in-band support for trap forwarding.
• The Drift and Reconcile process does not show a drift in device configuration for SNMP v3 trap configuration that EFA has pushed. However, every time the device update operation runs, EFA checks if the device is configured to send traps to EFA and if not, pushes the configuration again.
• For a multi-node deployment during failover of the active node, some traps might be missed while the SNMP service is bootstrapping on the new active node. There is no loss of traps if the standby node goes down.

gosnmp-service

The gosnmp-service is responsible for persisting the trap subscribers, receiving the SNMP traps, and forwarding them to the subscribers.

The service is stateless, so no historical data (that is, previously received traps) will be persisted.

For high availability deployment, the service will be running in active/active mode, however since the VIP is bound to one host at a time, the pod running on the active node will be the one receiving the traps. On failover, the standby node takes over and the SNMP service running on that node will forward the traps.

You may have multiple IP subnets configured to access EFA. In such a case, EFA creates multiple subinterfaces under the management interface to which EFA is bound. EFA does not determine which interface sends out the trap, syslog or webhook. The administrator is responsible for configuring a route to the recipient. If one is found, the server will send out the trap. For more information, see Multiple Management IP Network.