Description

This article explains the special configuration requirement for SNMP to work on loop back interface.

For other SNMP configurations please refer to KB16545 - SRX Getting Started - Configure SNMP Agent [juniper.net] .

Symptoms

You may encounter the following errors when polling to loop back interface.

  • No response

  • Connection timeout

  • Authentication failures

Solution

This issue can occur if   lo0  is specified under snmp interfaces but not on the external interface through which the lo0 is reachable.

Add the external interface to snmp interfaces through which the lo0 and SNMP agent communicates. It is not necessary to add snmp  to host-inbound services for external interfaces. This issue will not be seen if no interfaces are specified under "snmp interfaces". Please make sure the necessary security policies are in place to allow communication between external interface and loop back (lo0).

Related Information